PHILIPPINE PLANNING ~.r> JOURNAL ~

• VOL. XVII, No.2, APRIL 1986 •

PHILIPPINE PLANNINGJOURNAL:5 ~.r> 'co . . .'

C") ".

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zen~ SCHOOL OF URBAN AND REGIONAL PLANNING

PHILIPPINE PLANNING JOURNALVOL. XVII, No.2, APRIL 1986

Board of EditorsDolores A. EndrigaTito C. FirmalinoJaime U. Nierras

ManagingEditorDelia R. Alcalde

Circulation & Business ManagerEmily M. Mateo

Production ManagerRemedios R. Soriano

The Philippine Planning Journal is published in October and April by the School of Urbanand Regional Planning, University of the Philippines. Views and opinions expressed in signedarticles are those of the authors and do not necessarily reflect those of the School of Urban andRegional Planning. All communications should be addressed to the Business Manager, PhilippinePlanning Journal, School of Urban & Regional Planning, University of the Philippines, Diliman,Quezon City, Philippines 1101.

Annual Subscription Rate: Domestic, P40.00; Foreign, $12.00.Single copies: Domestic, P20.00; Foreign, $6.00.Back issues: Domestic, P10.00fissue; Foreign, $6.00/issue.

TABLE OF CONTENTS

The Application of Threshold Analysis in theEvaluation of Urban Expansion Area: San PabloCity as a Case Example

-Sirous Saljoughian Esfahani

22 The Use of Thematic Maps in Analyzing SoilErosion Susceptibility of the Philippines

-Romeo C. Bruce

29 Problems of Developing a Local Land Policy:The Case of Santa Rosa'

- Tito C. Firmalina

38 Economic Valuation of the EnvironmentalQuality Effects of Development

-Zenaida A. Manalo

48 About the Contributors

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CANlUBANG

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HIGHWAYS

NATKlNAl ROADS

LOCATION MAPSAN PABLO CITY

RAIL ROADS

THE APPLICATION OF THRESHOLD ANALYSISIN THE EVALUATION OF URBAN EXPANSION AREAS:

SAN PABLO CITY AS A CASE EXAMPLE*

SIROUS SALJOUGHIAN ESFAHANIGraduate Student

School of Urban and Regional PlanningUniversity of the Philippines

INTRODUCTION

The formulation of a rational plan of actionwhich could allow for the best possible use ofexisting resources and the most effective protection of the physical milieu constitutes afundamental aim of urban planning. The development of this rational planning strategyacquires urgency particularly jfl the large urbancenters of the P.hilippines that exhibit highpopulation growth rates. It is a common observation that the requirement for land for urban use correspondingly increases with population growth; however, the land that shouldabsorb the new population may be inadequateor may not be suitable for urban expansion ordevelopment. Often, there are impedimentsthat stifle the spontaneous and even growth ofhuman settlements and these usually includephysical geographic and economic factors. Indeed, the availability of suitable land for theanticipated growth of urban activities is a majorconsideration for a well-planned urban expansion.

In choosing the best areas for urban expansion, the criteria of development suitability andfunctional value of these areas stand out for

*This paper is based on the author's research for amasteral thesis in Urban Planning which was SUJmittedto the School of Urban and Regional Planning, Univer

sity of the Philippines.

1

consideration. Land suitability evaluation thenbecomes a vital exercise in urban planning. Theevaluative process involves an investigation ofthe constraints (and potentialities) of the wholeurban area. The significant constraints are bothphysical and economic and assumption in urbanplanning is that these constraints are surmountable. The preliminary evaluation that should bedone involves the delineation of the constraintsto be overcome arid the subsequent estimationof the costs that the solution to the constraintswould entail. The process of analyzing thedevelopment costs usually involves a rather elaborate physical and investment assessment thatwill ensure proper land use and economic viability. In coming up with a basis for rationaldecision-making in locating areas for new urbandevelopment, one technique-threshold analysis-presents itself as appropriate for dealingwith the assessment processes. Other reinforcing methodologies related to threshold analvsis that may be employed are map overlayand eco-engineering analysis.

Threshold theory and analysis was pioneeredby Professor B. Malisz of the Polish Academyof Science in the early sixties in Poland, whereit is now a widely used tool in planning. Themain basis for the development of thresholdtheory was the observation that expandingtowns are faced with limitations imposed byphysical geographic features, existing land uses,infrastructure services and public utilities.These limitations, a common phenomenon inthe growth of human settlements, are calledthe thresholds of urban development. Their

PHILIPPINE PLANNING JOURNAL

main characteristic is that they are not irremediable, but, on the other hand, they can beovercome only at a disproportionately high percapita cost.

With its major stress on identifying and measuring the cost dimensions of thresholds, thresholds analysis provides a relatively. simpleframework for evaluating and guiding planningdecisions. Primarily, the technique allows oneto measure the development costs of alternativegrowth areas using a consistent and structuredstrategy. In this way, those areas which arecheaper to develop, or those that are mostreadily or easily serviced, can be identified.During the process of analysis, the investigatorcan appraise alternative growth options, explorefinancial implications and explain planning andengineering assumptions for a better decisionmaking procedure.! This study tries to applythese and other methodological techniques tocome up with firmer bases for gUiding growthin a Southern Luzon urban center: San PabloCity.

STATEMENT OF THE PROBLEM ANDGENERAL OBJECTIVE

In the field of physical planning, rationalization can be defined as the search for the bestof all possible alternatives, keeping in mind theultimate ends desired. "Rationalization necessitates the division of the whole planning process into sequential parts so that the validity ofeach successive conclusion, drawn logicallyfrom the preceeding step and leading to thenext one can always be checked on the basis ofprevious premises.,,2

The evaluation of plans in the urban planning process in the Philippines is usually

1James Smith, "Threshold Analysis of Two Poten

tial Metropolitan Growth Corridors: A Melbourne CaseStudy, " Town Planning Review, Vol. 53, No. 2(1982), p. 200.

2United Nations, Threshold Analysis Handbook,Department of Economic and Social Affairs (, 977),p.33

2

achieved by intuition or subjective analysis. Except for some sporadic cost-benefit analysis,planners hardly use such complementary me:thods of plan evaluation as the thresholdanalysis, planning balance sheet or the goalachievement matrix. Although purely intuitiveplanning may bring outstanding results in specific cases, it also may lead to waste of capitaland resources, considering that it usually involves the trial and error method. It is, therefore necessary to undertake planning moresystematically by applying evaluation techniques that act as the main safeguard and control device towards the reduction of subiectivitv.

The application of this analysis where theforces of urbanization are often uncontrolledmay provide as its main result evidence on theirrational and uneconomic nature of some ofthe development that is currently being performed, which in turned may not only bringabout serious problems in the future but alsowastage of scarce resources. The present studytries to apply this technique and to analyzehow far this te~hnique can contribute to afuller conception of the planning process andthus rationalize urban planning practice.

The present study has followed the generalmethod formulated in the threshold analysismanual of the Scottish Development Department. For analyzing physical-geographic features and infrastructure and utilities and theirconsequent thresholds, eco-enqlnneririq is_'!pplied. The combination of these techniqueswill allow evaluation of various physical aspects, costs and investments involved in overcoming the constraints as well as allow the formulation of physically suitable and economically viable alternatives for development.

The study attempts to answer the followingquestion: What major threshold in terms ofland uses and selected infrastructure and utilities are likely to be encountered by San PabloCity in its future expansion? The pursuit ofthis problem will involve the calculation of thethreshold costs of overcoming the constraintsto be identified. Thus, as a general objective,the study attempts to evaluate the contributionthat threshold analysis makes in urban expansion planning but always with the recognition

of probable modifications that Philippine conditions may impose as in the case particularlyof San Pablo City as the study area. It will alsotake careful note of conceptual and proceduralproblems that may be encountered for thebenefit of future applications.

OPERATIONAL OBJECTIVES

The research undertaking, which shall focuson a study of technological thresholds, has thefollowing operational objectives:

1. To define the best overall pattern of physical growth of San Pablo City for planning its distant future expansion usingphysical geographic frameworks.

2. To define the threshold limitations of urban residential expansion for the nearfuture (year 2000) using physical geographic and selected infrastructure and utility frameworks.a. To identify suitable areas or evaluate

proposed areas of urban expansionspecifically for residential purposes.

b. To supply the comparative thresholdcosts of identified expansion areas.

SCOPE AND DELIMITATION

The geographic scope of the study is theCity of San Pablo which is noted for its diversity of topography and surface waters. Thewhole territory of San Pablo City is an idealplace for the application of a thorough ordetailed threshold analysis. The land area ofSan Pablo City, however, proved too extensivefor an individual researcher to handle. Therefore, only a basic threshold analysis was carriedout for the whole area while the basic and costanalyzes were done for the urban area only.

The scope of the second objective of the study, however, will include more or less 3-kilometer radius designated urban areas for expansion of the settlement that will accommodatethe additional population by the year 2000. Itis primarily concerned with the direct threshold costs and does not comprehensively undertake economic evaluation of the area. The process is also primarily concerned with the development of residential areas and selected supporting infrastructures and utilities. Informa-

3


tion on other land uses, however, is indirectlyinvestigated.

STUDY AREA

The study area is San Pablo City which is thesouthernmost community in the province ofLaguna. The city is one of the progressive citiesin southern Luzon. It is accessible from sevenpoints by road to neighboring municipalitieswhich consider the city as their center of trade,commerce and major services.

The recent effort of the qovernrrreht to develop Calamba and San Pablo in Laguna and thecities of -Batangas, and Lucena in Quezon asthe"Growth Corridor Sub-Region" for RegionIV has positive influences on the city's futuregrowth in terms of improving the existing transport infrastructure in these areas. The imposition of a 50-kilometer radius ban against theestablishment of new industries within Metropolitan Manila has also led to the location ofsome industries in San Pablo. These facts havesupplied the basis for the selection of the cityas the study area.

The city also has been selected by the thenUniversity of the Philippines Institute of Planning (now School of Urban and Regional Planning) and the Department of Agrarian Reformas a primary sub-region urban growth centerwithin the Southern Tagalog region. Accordingto a report made by these two institutions, the.regionalization scheme intends to emphasize"the need for effective integration of the country's land reform program with the equally important industrialization and urbanization program of the government." A -growth center ischosen for future urban expansion. The ba~is

for this choice is the "composite and relativeadvantage of the individual municipalities andcities with respect to their population size, percent urban population and rate of populationgrowth, the range and supply of goods and services they offer and their general stage of development and/or economic specialization."

As mentioned earlier, the study aims to findthe areas that offer the best site or sites forurban residential expansion as well as to analyze and compare the costs of developing thesesites for urban expansion up to the year 2000.


• Figure I: ZONING MAP, SAN PABLO CITY

N

SCALE: 1:100,000 MTS.1.0~

o.'V~

~G·1 ,p..O Legend:

D RESIDENTIAL

fIi!B COMMERCIAL

~ INTITUTIONAL

4

.../

~ INDUSTRIAL

~ PARK a OPEN~ SPACES

I~~" CIRCUMFERENTIAL\'~' I ROAD--'

In this regard, some particular areas from threemajor sites proposed by the City government'sCity Planning and Development Staff (CPDS)(Fig. 1) which are suitable for industries,commerce and recreation as indicated in thecity's land use plan have been adopted for thepresent study, and assumed as given for furtheranalysis.

METHODOLOGY

In arriving at the first operational objectiveof the study, a series of inventory maps wereobtained from different sources and reproducedfor the whole study area. Maps on such factorsas topography; soil, underlying rock formation,surface water, watershed areas and present andproposed land uses were utilized. To achievethe first objective wh ich involves the search forthe best overall long range growth direction,another series of maps were produced to analyze various physical geographic features andthe possible thresholds imposed by them to urban development. Some. of these thresholdswere presented in a single map. In each map,land was divided into three classes of suitability, namely: land immediately suitable at nothreshold costs, land suitable at some thresholdcosts and land unsuitable for developlment. Thefollowing criteria were adopted for identifyinglands unsuitable for future urban expansion:

1. Lands with altitudes of more than 200meters above sea level because all the natural sources of water are located along orbelow this level;

2. Lands with slopes of more than 15% dueto the high degree of erosion;

3. Lands already designated for other futureurban functions;

4. Prime agricultural lands which are protected by existing policy considered asclass A, provided they do not hamper theurban continuity and use of existing infrastructure and utilities.

A shading procedure was adopted to presentjifferent classes of suitability. For the physicalgeographic analysis dark shading was used forunsuitable land and light shading for land suitable at some threshold costs. The land suitableat no threshold cost was left blank. The synthesis map was produced through superimposi-

5


tions of criteria maps. The suitability maps withthe first and boundary threshold lines weretraced. The first threshold line encompasses theexisting built-up areas and immediately suitableland. The boundary threshold line is the linebeyond which development is not feasible orrequires high threshold costs. The intermediateareas are bounded between the first and boundary thresholds and require some threshold costfor their development. Furthermore, the finalsynthesis map was presented in a grid system,and unsuitable land was eliminated from further analysis. The grid system represents thebasic unit which is the basis for the succeedinganalysis and is discussed further below.

The methodology for the second objective islargely derived from the procedure outlined inthe Threshold Analysis Manual. The second objective differs from the first in its scope andmethod of analysis applied. This objectivesearches for the best residential expansion forthe urban areas in the near future (year 2000)using the results obtained from the physicalgeographic analysis plus analysis of ~elected infrastrucutre and utility services. Four basicurban services were selected for analysis, nameIy: water supply, power supply (electricity).road system, and drainage - all threshold causing factors for future residential development. The sewerage system was not includedbecause it is estimated by the San Pablo CityWater District feasibility studies that a separate sewerage system and the correspondingsewage treatment plant could cost close toP50 million based on 1983 prices. This cost isbeyond the paying capability of the city andthe Water District.i' On-site disposal system ispractised by the people. The suitability andpossible threshold factors by this kind of disposal is incorporated in the soil analysis.

During the preliminary analysis, it was foundout that the urban population increase in thetarget year is not a significant number and thatthe suitable areas identified from the physical

3Local Water Utilities Administration, (Ministry ofPublic Works and Highways), Feasibility Study Reportfor the -San Pablo Water District, Phase 1/ Improvement, 1982, p. 4-14.


Fegure 2 HIERARCHIES OF LAND SUITABILITY

INFRASTRUCTURE

Water supply analysisaccording to the year·of construction

Road (Accessibility)analysis according tothe type of pavement

Drainage analysisaccording to t.he ecological characteristic ofthe receiving body ofwater

Power analysis accordingto line copacity

PLand immediately

suitableI st

B

rn

RIOLitt Iecosts2 nd

E3

rn

R I TIE SThresholdinvolved

3 rd

B

OJ

Higherthresholds

costs

oo

oo

Different combinations may be obtained in the composite map

i.e., ~ • This sign shows land immediately suitable trom the stand

point of all the four factors cited above.

geographic analysis is much more than the landrequired for the residential areas. This lead thestudy to go to more details in identifying themost suitable areas at least threshold costs. Inthis regard, another version of eco-engineeringshading procedure was adopted to a grid system of nine hectares, representing a BasicUnit." The symbols in Figure 2 were deve-

4Basic Unit - The division of costs into "normal"and "additional" categories is fundamental to threshold theory, and threshold analysis concentrates onstudying and analyzing in particular "additional" or"threshold" costs. When carrying out threshold analysis, "normal" cost must be held constant. Normalcosts are the costs of providing services within the areaof-basic residential unit. This includes the cost ofconstruction, site development and servicing whilethose that are incurred in providing the services to thatunit are additional costs. The division of costs is donethrough the adoption of basic units for which a standard residential density and mix of dwelling types hasbeen set.

The basic residential unit is a group of dwellings together with the land that is made available primarilyfor the use of the residents. It may vary in size-1, 4 or9 hectares or sometimes even larger. The use of theunit would at/ow for an easy conversion to computermapping should the wider application of the thresholdanalysis be made in the future.

6

loped to show hierarchies of suitability for eachparticular infrastructure and utility being investigated.

The thresholds imposed by infrastructureservices are due to capacity limitations of oneor more of the components in the system. Inthe present case, the components of each service were separately analyzed to determinewhether any spare capacity or deficit existed inthe system. Space capacity is defined as the remaining capacity in the existing or adjusted systems when they are used by the current numberof users at target date standards.

In the case of water supply components, inaddition to the existing components, the proposed sources, the reservoirs, and the distribution system were also analyzed and their sparecapacities and thresholds identified. The reasons for including the proposed plans of watersupply and analyzing them as existing ones wasthe availability of completed extensive feasibility study for expansion and improvement ofwater supply of San Pablo City in two phasesup to the year 2000. This objective also coincides with the target of the present study. Theinclusion of the data from the feasibility studyallowed the consideration for analysis of landsplanned for future use. These lands would

otherwise have been simply eliminated on account of current non-usage. The capacity threshold of the power supply system was similarlyinvestigated. No capacity threshold was identified in the existing road system.

The composite map produced by superimposing the results of each infrastructure andutility system revealed several suitable areas forfuture urban residential expansion. Three alternatives were selected for further analysis. A gridsystem was adopted for each alternative assumed to serve as a street system. Comparativethreshold cost analysis was performed for thefour infrastructure and utility systems of eachalternative, resulting in the identification of thebest residential expansion through lowest percapita costs involved in their development.

LAND CAPABILITY ANALYSIS FORURBAN EXPANSION AND DEFINITIONOF FIRST AND BOUNDARY THRESHOLDS

This section tries to achieve the first objective of the study which is to define the bestoverall physical growth and expansion of SanPablo City based on physical geographic features. To accomplish this objective, eco-engineering map analysis was conducted whichsubdivided the whole territory of the city intothree categories of suitability for development(Fig. 3). This was achieved by analyzing separately some factors that cause major limitationsto future developments. Various symbols wereselected for each factor showing the degreesof suitability. The underlying rock formationcharacteristics were incorporated in the soilsuitability map using horizontal shading. Vertical shading was used for preserved watershedareas and main bodies of water as being unsuitable for development. Diagonal lines showdifferent land suitabilities according to thetopography of the area. These maps were superimposed with one another producing a synthesis map (Fig. 3) capable of showing all aspectsanalyzed with the areas having more shadingbeing less suitable and blank areas as immediately suitable for development.

The first threshold line contains all the areasthat, from the view point of the group of threshold generating factors under consideration, are

7


"immediately" suitable for urban developmentat no threshold costs. This line was drawn mostly from the results of slope analysis in thesouthern parts and the combination of slope,soil and underlying rock analysis in thenorthern parts. Boundary threshold deal withthe definition of the factors that generate somesort of boundary limitations on urban development in general. It may be due to natural andman-made environment and because of the"dominant" non-residential functions. Theboundary threshold is the line beyond whichdevelopment is not possible or requires veryhigh threshold costs; The boundary thresholdline was drawn along the contour line which is200 meters above sea level. The major reason,aside from the expected higher cost of sitedevelopment and services is the presence ofpotable sources of water below this level. Administrative boundaries are not usually consideredas a Iimitati6n to development, but since thescope of the "study is limited to San Pablo City,the administrative. boundaries constituted theremaining portions of the boundary threshold.

Intermediate thresholds, in turn, delimitareas that can be made suitable for development only at the expense of the costs involvedin overcoming particular thresholds. These areasare therefore lying between the first and boundary thresholds. As shown in Fig. 3, intermediate areas are mostly located along the westernportion of the city. Fig. 3 was further converted to a grid method representing the basicunit of nine hectares (Fig. 4). This figureshows various existing and proposed land usesand also land suitabilities analyzed earlier. Furthermore, an imaginary boundary thresholdline was drawn in the form of a square aroundthe existing urban area with distances of morethan four kilometers from the center encompassing different land suitabilities and urbanfunctions for further analysis of urban expansion areas. This area was enlarged twice (scaleof 1:50,000) and is used for evaluation of urban expansion areas of second operational objective.

Findings on the first objective. The first objective is to define the best overall physicalgrowth of the city for its distant-future expansion using physical geographic frameworks:

Legend:

NSCALE: I: I00,000 MTS.


Fiour. 3: PHYSICAL - GEOGRAPHICSYNTHESIS

8

LAND IMMEDIATELYSUITABLE

LAND SUITABLE AT SOMETHRESHOLD COST

LAND UNSUITABLE FORDEVELOPMENT

BOUNDARY THRESHOLD LINE

FIRST THRESHOLD LINE


~ EXISTING BUILT UP~ AREAS

mmn PROPOSED COMMERCIALIill1IlI AREAS

~ PROPOSED INDUSTRIALE3 AREAS

~ PROPOSED PARK a!£ill OPEN SPACES

LAND IMMEDIATELYSUITABLE

BOUNDARY THRESHOLDLINE

LAND SUITABLE AT SOMETHRESHOLD COSTS

LAND UNSUITABLE FORDEVELOPMENT (BODIESOF WATER SWAMP)

NSCALE: 1:100,000 MTS.

Legend:

Do~

•

Figure 4: LAND SUITABILITY MAPBASED ON PHySICALGEOGRAPHIC FEATURES

9


The map analysis revealed that suitable landfor development is abundant all around theexisting urban areas. (See Fig. 4). From theresults of the physical geographic analysis usingthe map overlay method, four distinctive subareas were identified, characterized as follows:

1. The Northwestern portion - This areaconsists of lands with different characteristics that are capable of producingdisproportionately high threshold costs ifa continuous urban expansion is desired.Such costs would entail those on reclamation of swampy lands, construction ofretaining walls for areas with steep slopes,increasing the length of linear elementsfor rolling areas, construction of drainagefacilities on extremely flat land withclayey surface soil that is susceptible tooccasional flooding and the presence ofunderlying rock near the surface whichmay also produce higher .costs due to excavation for utilities.

The advantages inherent in this areaare its nearness to Manila and the presence of water mains, electricity and asphalted roads which all present attractions for expansion. This area is mostsuitable for commercial and small scaleindustries.

2. The Southwestern portion - This area isbigger in size than the northwestern portion and is predominantly flat land with aslope below 1 percent. It consists ofprime agricultural land class A and almostall the rivers and creeks of the city arepassing through this area which makes itmore suitable for agriculture. A majorityof rice plantations are located in this area.Its very flat slope, however, makes thearea susceptible to flooding and also presents difficulties with regard to the futureconstruction of a sewerage system due tothe slow movement of the sewage. Thereare two disadvantages with regard to pollution. Firstly, there is the presence oftwo polluted rivers and, secondly, theprevailing winds have a northeast-southwest direction that can bring the noxiousfumes of the existing industries to thearea.

10

3. The Southeastern portion - This portionof the city possesses better overall development characteristics compared .withthe above two identified areas. The gentleslope of the land is favorable for development. The area appears to require theleast drainage facilities. There is no majorlimitation identified in this section of thecity.

4. The Northeastern portion - This areacontains the seven famous lakes of thecity. It is surrounded by mountains andhills in its outer boundary. The area hasgood potentials for tourist development.The dominating slope is gentle. The onlydisadvantage that can possibly be mentioned would lie in the rather uneventopography that may prevent the continuity of urban expansion.

Second Objective

The second objective primarily deals withthe definition of the first and boundary threshold for the selected infrastructure and utilityservices, as a means to search for the best residential areas for the population which is expected to increase in urban areas by the year2000 (projected to be about 12,404 people).The infrastructure and social services havethresholds that cannot be expressed as an areaon the ground, since they are due to capacitylimitations of the components of each of theservices. These components, as in the case ofwater supply, may be the central works such asheadworks, treatment works, storage reservoirsor the networks of pipes. This system is analyzed to find out if there is any spare capacityavailable or if a deficiency exists. In accomplishing this objective which is also based onthe findings of physical geographic analysis,maps of larger scale (1:50,000) were producedto exclude the land which is not expected tobe developed in the near future. These mapswere divided into nine-hectare basic unit grids.

In the first step of the analysis, the watersupply system lent itself to a more thoroughand definitive threshold analysis compared toother utilities. This was due to the existence ofan elaborate feasibility study for the expansionof the system which will be implemented in


two phases up to year 2000. This is incidentallyalso the target year of the study's second objective. The availability of such a study allowed theauthor to conduct a direct analysis and toadopt its plans as well as to present the investigations in line with the water system analysis.This was done despite the fact that the scope ofthe feasibility study includes both the urbanand rural areas of San Pablo City while thescope of the second operational objective ofthis study covers urban areas only. This adoption diverted the procedure of the analysis awayfrom the one outlined i,n the Threshold Analysis Manual of the Scottish Development Department.

The direct threshold cost analysis was tosome extent modified. (Threshold costs are further discussed in the succeeding pages). Thismodification was largely caused by the natureof the costs involved in central works and maindistribution system which include whole urbanand rural areas with a population range wider.

than the assumed one for the urban areas. Fig.5 shows the thresholds that the whole citywill encounter due to existing and proposedwater sypply system planned by the San PabloWater District in three phases: Phase I completed, Phase II is exptected to be completed in1990 and Phase III in the year 2000.

From the four infrastructure and utilitiesanalyzed, only the water supply suitability analysis is presented as an example. For this utilitya thorough study was conducted regarding theavailability of water resources, domestic waterdemand, existing source facilities, proposedsource facilities, etc. for the whole city and alsofor urban areas in particular. Fig. 6 showsthe version of eco-engineering adopted forurban water suitability analysis which is basedon the main distribution system. The same procedure was used for drainage, road and powersupply analysis. Four maps were producedwhich were integrated to produce the composite map, (Fig. 7) which combined all the

Figure 5:FIRST AND BOUNDARY CAPACITY THRESHOLD OF EXISTING AND PROPOSEDFUTURE COMPONENTS OF WATER SUPPLY SYSTEM

YEAR 1980 I9llt1 1990 1995 2000------ I 1 .::::::;:1-----====:.----, • IPOPULATION TO BE 60 93 liB 152SERVED IN ('000)

I. OPERATION STORAGE

5300 m3 .591m3

=t7325 m3

2. SOURCE OF WATER

t 555 L /SI

BOUNDARY THRESHOLDFOR THE PROPOSED

L-_--:--=~:-:-:=------ SOURCE COMPONENT

SYNTHESIS OF PARTIALCAPACITY DIAGRAMS

THE CAPACITY OF RESERVOIR WOULD CAUSE THRESHOLD IN THE AREA BY YEAR 1990.THE SOURCE CAPACITY IS NOT CRITICIloL FOR URBIloN IloREIlo BEFORE YEIloR 1990

Legend :~ Capocify token up by --r-~ existing population -----l-

~ Spore copacit)' up to ~~ first threshold ~

=mmn Capocit)' that can be pro-, ,----~

vided by extending the .L..-._.txisting components 0' ' -threshold cos, (not Q'Ioi-tcbte )

Boundary threshold forone component of OresystemBoundary threshold ceinci<les first thf"eshol<l

Capocit)' 'hot con be provided or thresho,d cost byconstructino new components

11


Figure 6: WATER SUPPLY SUITABILlT.,N

SCALE: 1:50,000 MTS.

Legend:

D LAND WITH SOME ~ EXISTING URBANTHRESHOLD COST ~ AREAS

B L AND ADJACENT BY EXIS- IllIllI PROPOSED COMMERC ALT1NG MAIN (IMMEDIATELY ISUITABLE) AREAS

B LAND TO BE SERVED BY ~ PROPOSED INDUSTRIALPHASE II (2nd PRIORITY) ~ AREAS

E3 LAND TO BE SERVED BYPHASE In (3rdPRIORITY )

12


Figure 7 : COMPOSIT E MAP

SCALE: I: 50,000 MTS.Leg8Ad :

1st 2nd 3rd 4th

B BBD WATER ~ EXISTING BUILT UP AREAS

z 000 POWER ~ PROPOSED INDUSTRIAL AREAS

!S16J ISJO DRAINAGE !IlIlll PROPOSED COMMERCIAL AREAS

[]]Q]CDO ROAD

13


results and showed major suitable urban expansion areas. But this composite map due to unavailability of the physical layout of ruralbarangays close to urban areas and the presenceof utilities along the road networks, the resultof the synthesis or the convergence of suitablecriteria came out mostly along the road system.The eco-engineering symbols were selected topresent the basic units as having more shadingto denote greater suitability for development.This procedure permits the updating of thecomposite map as more services are introducedto the area or any of the existing services is improved to a higher degree of suitability. The updating procedure is quite simple and can beconsidered as one of the advantages of eco-engineering technique over other methods such assieve method wHich uses coloring with different intensities. The composite map is self-explanatory, with each grid representing its potentialities and constraints at once, facilitating theintegration of various combinations of basicunits to form continuous areas for urban expansion.

The concepts of Neighborhood Unit and Environmental Area have been brought into consideration in aggregating various combinations ofbasic units also called "Grouping." Threegroupings from the composite map were identified. Some groupings were eliminated on account of their being crossed by a rail track, polluted rivers or being less suitable in comparisonwith the selected ones. The area of each grouping is approximately 171 hectares which isequal to 19 basic units of 9 hectares each, calculated from gross density analysis. The threeidentified groupings were further analyzedthrough isolation and adjustment of the grids(Fig. 8). This adjustment was done based onexisting road alignment and closeness of anatural stream for the storm disposal of thegroupings.

Grouping I as an example is presented here(Fig. g). For each three groupings, a separate distribution of water and power (regardlessof central works) were designed. Similarly, adrainage system based on the intensity of rainfall and characteristics of surface and underly"iog soil were designed to collect the rainfall ofeach basic unit to the nearest stream. For the

14

road systems, new local and district roads toserve the basic units together with the bridgesand culverts were separately designed. The totalthreshold costs imposed by the four infrustruc'ture and utilities were calculated based on percapita costs for the selection of the most suitable groupings for the future urban residentialareas by the year 2000.

THRESHOLD COST ANALYSIS

Threshold analysis permits identification ofdevelopment constraints or thresholds restricting further physical expansion of the city, andcalculation of the costs of overcoming theseconstraints. Thus, it permits not only the defining and characterizing of alternatives forphysical urban expansion, but also the assessingof the differences in investment costs. The totalcosts necessary to locate a new unit of physicalurban expansion in a town (Ct) are at least twofold:

1. Costs that are contented with the locationof the unit but that constitute the "normal" costs that have to be spent in anycase (Cn=normal costs). Normal development costs as attached to some set ofideal characteristics represents theconstant part of development costs, thatis, the part that always has to be spent fora given type of development regardless ofits location.

2. Costs tied to the existing conditions andcharacteristics of a given natural and manmade environment. These constitute additional costs substantially varying fromone location to another (Ca= additionalcosts). .

Threshold analysis is usually concerned withthe second group of costs, the calculation ofwhich are undertaken in this study. Throughthis technique, various alternatives are compared by means of a single common denominator, namely, threshold costs. The indices of"efficiency" can be found by dividing the threshold costs (of various alternatives) by the number of new inhabitants expected to be accommodated. The main implication of threshold indices is that the lowest per unit threshold costs


,,\("

Figure 8: SUITABLE GROUPINGS @N

SCALE: I: 50.000 MTS.

Legend:

BASIC UNIT

EXISTING BUILT UPAREAS

PROPOSED COMMERCIALAREAS

PROPOSED INDUSTRIALAREAS

CONCRETE &ASPHALT ROAD

-- RAIL ROAD

DIRT ROAD

15


Figure 9: GROUPING 1

N

SCALE 1:20,000 MTS

Legend

c=J BASIC UNIT

~EXISTING RESIDENTIALAREA

=----*EXISTING ASPHALTROAD

+l-t+tH-tttt- RAIL TRUCK

~ STREAM

REQUIRED BRIDGE

REQUIRED ROAD

____ -'- REQUIRED DRAINAGEI PIPE

REQUIRED WATER 8POWER SUPPLY LINE

REQUIRED DISTRICTROAD

16

constitute the most economical provided thatall other effects can be assumed to be equal,l.e., the living conditions are kept within thesame accepted standards. However, in some particular cases the decision may vary in favor ofother aspects such as socio-economic factors. Inany case, the decision maker will at least knowthe cost of the alternative concerned.

This section discusses the threshold costsassociated with the construction of new infrastructure and utilities that are required for theaccommodation of the estimated population ofthe urban areas, and therefore accnmplishingthe second objective of the study.

The direct threshold cost analysis applied inthis study was to some extent modified with regard to the definitions discussed above. Thismodification was largely caused by the natureof the costs involved in central works and maindistribution systems of water and power supplies which include whole urban and rural areaswith a population range wider than the assumedone for the urban areas. Any expansion of thesesystems will affect the whole city and the distinction of the costs for urban and rural areas israther impossible. It is also assumed that thissituation is a typical case in other cities of thePhilippines. It was therefore decided to comeup with two categories of direct thresholdcosts namely:

1. Direct threshold costs, which include thewhole of the city and are pre-requisite ofany expansion and cannot be expressedin terms of per capita cost for the population increase in urban areas and consequently cannot act as a determinate factor in identifying the suitable areas forurban expansion (groupings). For example, in the case of water supply systemcosts: under this category were those ofequipment and civil works for intakeboxes transmission/distribution, reservoirs, booster pumps, some internalnetwork, stored material, disinfection,fire hydrant, service connection, servicevehicles, land acquisition, deep-well pumpand pump house, for both phase II andIII as well as cost of .power supply substation including foundation, transformerdisconnect switch and power fuses,

17


switchboard, conducts control cable,grounding system, which, all together,based on 1985-86 prices totalled166,118,600 pesos.

2. Direct threshold costs include only the estimated population to be accommodatedand are used as basis for selection and expansion of different alternative areas.These costs-will appear as per capita costfor construction of drainage, roads, distribution of power and water for differentgroupings for urban expansion. Thesecosts included the cost of water andpower supplies to the basic unit (disregarding the central works) and costs ofnew local and district roads plus bridgesand culverts.. Grouping III was found tobe the most economical for developmentwith a total cost of 40,128,861 pesos.The total costs of groupings are presentedin graph form for comparison. (Fig. 10).

Summation of the first and second categorythreshold costs gives an indication of theamount that the city needs to overcome its major threshold costs up to year 2000. Thus:

P166,118,600 + 40,128,861 = P206,247,461

CONCLUSION

Based on the research problem, objectivesand findings of the study, the following conclusions are put forth:

1. The study has shown that subjectivityand intuition in urban planning can be reduced by the evaluative techniques ofthreshold analysis, and eco-engineeringmap overlay, which have shown themselves to be more systematic, accurateand rational.

2. The study shows that through thresholdanalysis and related methods, wastage inland use and consequently capital resources can be avoided. The city plan has allocated much more than enough land within a three-kilometer radius for residentialuse while the study has revealed that onlyabout one eighth of the residential area


4!5444'1424140393837363~

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atn 212019i 18

III 17.1&1 16! 15_ 14

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"10I

•765432I

._.

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, Ir- .

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YEAR 1985

Legend:

GROUPING ! _ _ Figure 10 : STEPPED THRESHOLD COST DIAGRAM

2 4 5 6 7(NO.1190

I I 10 II 12 IS 14 15OF BASIC UNITS )

1115

us 17 18 II

2000

GROUPING 11- _._.-

GROUPING IU----

18

proposed by the city planners is actuallyneeded for such purpose up to the year2000.

3. It has been shown that a city will encounter physical limitations to its development due to topography, soil, existingland use,and technology of infrastructuresuch as water supply, power supply,drainage and transportation systems. Thestudy indicates further that these limitations or thresholds are not irremediablebut can be overcome at "additional"development or threshold costs.

4. The procedure allows flexible planning,i.e., the identification of urban growthpossibilities, by indicating the varyingcosts of these possibilities, which in turnprovides a basis for further urban design.The flexibility afforded by the methodsalso provides planners ample basis forboth short-term and long-range planning.

5. The study proves that threshold analysisis applicable to Philippine urban conditions as they occur particularly in SanPablo City. As shown by the study, however, there is a need for the technique tobe tailored to Philippine conditions andto be supplemented by related techniquessuch as the map overlay method of ecoengineering. The study to some extentdiverged from the process outlined in thecommonly used Threshold AnalysisManual of the Scottish Development Department, largely because of the prevailing service-where-ever-the-people-go policy of the city authorities.

RECOMMENDATIONS

As applied in the findings of the study, thefollowing are the recommendations made forthe development of San Pablo City:

1. Based on the map overlay analysis (ofphysical geographic factors), urban expansion should be directed to the southeastern portion of the city (See Fig. 4).This portion has gentle slopes, requiresthe least combined drainage facilities andbridges, and encounters no major physical

19


limitations and the agricultural lands aremoving from Class A to Class B.

2. More specifically, urban residential expansion should be sited within the 170hectares of Grouping III (See Fig. 8)in the southeastern portion of the City.This is because Grouping III has the leastthreshold cost compared to Groupings Iand II.

3. The proposed industrial site which happens to be adjacent to Grouping IIIshould be relocated to the left side of therailroad (See Fig. 8) which is closer tothe proposed commercial area. However,if the industries to be set up are non-pollutive, it is better to retain the proposedindustrial site to provide proximate employment opportunities as is suggested inthe Planned Unit Development (PUD) approach.

FINAL REMARKS

Possible constraints to the application ofthreshold analysis in developing countries arisepartly from the nature of the analysis and partly from the nature of the method, which was,as noted earlier, originally developed andfound applicable to industrialized socialistcountries. The technique has generally foundacceptance in such countries as India, Syria,Uganda, Caribbean, Malaysia, Brazil, Iraq,Nigeria, Venezuela and Mexico. Observationsfrom these countries show that interest inthreshold analysis is not limited to one country,nor, is it limited to a single continent. Interestis worldwide and increasing. Moreover, growinginterest in its use appears to be particularly evident in countries with rapid development andurbanization rates. s

In the Philippines, threshold analysis shouldnot be too difficult to adopt considering thatpreference is generally given to outward expansion rather than vertical growth of cities. Thus,there is the seeming popularity of suburbansubdivision development while on the otherhand urban renewal cannot seem to take off.

SThtwhold Analysis Handbook, op. cit., p. 25.


Moreover, urban developments in this countryare largely accounted for by private investments. Threshold analysis can be used by citygovernments to influence the location decisionsof private developers.

In the particular case of San Pablo City, thefindings of this study could now be used to revise the structure plan and the zoning ordinances. Then, a strict enforcement of the locationalclearance system in combination with positiveincentives to private developers should be ableto influence the direction of future growth tothe identified urban expansion areas. Suchpositive incentives may take the form of initialinvestments by the local government in infrastructures, utilities and services in the desireddirection. It is true, as Philippine experienceshows, that infrastructures and utilities havebeen used to service rather than shape development, but there can always be a first time.

Investment in local capital development isone major challenge that the findings of thisstudy poses to the capability and commitmentof the city government of San Pablo. If thecity government desires to redirect future urbangrowth to the identified areas, a threshold investment of some P206 million will be requiredup to the year 2000. Luckily for the city, partof the investments need not come from publicfunds. Some utilities such as electric powersupply and water supply are being developedby private or quasi-public agencies. These agencies normally shoulder the investment cost ofexpansion.

The present exercise shows nothing but interest for application of this techniques as a toolfor a better and more rational evaluation anddecision making in urban and regional planning.Threshold analysis has not been developed as acomprehensive tool for the economic evaluation but basically a location oriented techniqueintroducing the quantification of thresholdcosts in a physical planning technique and it isessential that its limitations be understood.Some of the limitations cited in the Manual are:

1) Threshold analysis does not take socioeconomic benefits into account and merely considers them as equal for the wholearea.

2) Assumptions are pre-requisite to the

20

application and the results of the analysismust be seen in relation to the assumptions made. Thus, comparison between anumber of towns may be difficult if different assumptions are made for each ofthem.

3) The cost calculations are often based oncrude assumptions and should not betreated as precise cost assessment.

4) The process is primarily concerned withthe development of residential areas andinformation on other areas is obtainedonly indirectly.

The benefits obtained from threshold analysis, however, outweigh. the limitations, particularly because the results of threshold analysiscan function as input data for other techniquese.g., Cost-Benefit Analysis, Planning BalanceSheet, OPtimization Method and Goal Achievement Matrix.

The procedure outlined in the ThresholdAnalysis Manual is not intended to be a rigidone, and can be tailored to any situation whilemaintaining the general framework of analysis.In this regard the procedure followed by thepresent study diverged from the process in theManual particularly in the way of identificationof thresholds and potentials by application ofthe eco-engineering technique. It is necessary toadjust the threshold analysis to the existingplans unless the planner has at least some control or influence over the existing plans andlocation of urban expansion, who can bring thedifferent planning bodies into close coordination to control the urban growth rather thancontinue with the policy of service-whereverthe-people-go. It is 'therefore necessary to adjustthe analysis in the most careful way and the significance of such adjustment must not beunderestimated.

It is the main aim of threshold analysisto identify the most suitable areas for urbanresidential expansion. The present study alsoconcentrated on the identification of this urbanactivity while other functions, such as industrial, commercial and recreational areas were assumed as given and were adopted from theexisting plans. It is suggested by the presentstudy that in future applications, if a high rateof trade and industrial growth is expected, the

residential areas should be analyzed in relationto other urban functions particularly as far asthe commuting patterns are concerned. In otherwords, the impact of residential groupings andemployment concentration and the commutingpattern should be investigated and should formthe basis of the road system. This was not doneby-the present study because the economic baseof the city is agriculture and the kinds of industry and the number of workers are not clearlyknown and industrial growth from the currentsituation does not seem to be very significant.At any rate, the design of the grouping of basicunits which provides for neighborhood servicecenter tends to reduce the need for trip making.

Some other aspects that shall be broughtinto consideration in future applications andare usually undertaken in parallel with threshold analysis are the land ownership (tenure).land speculation, political or legislative factorsthat may change the results of analysis drastically. These aspects were simply excluded,because the areas analyzed for urban expansionhave been zoned in 1975 for this function andinterviews with authorities have revealed nosignificant problems in this regard.

Nevertheless, it is reasonable to expect aconsiderable impact of this study on land valuesthat will require the application of appropriateurban land policies. For sure, once the identified urban expansion areas are made known tothe public, an artificial increase in marketvalues of affected lands will immediately occur.The capital gains tax should therefore be strictly enforced to enable society to recapture sucha speculative land value increment.

Similarly, unearned increment in land values

21


will accrue to private property owners immediately benefited by public investments ininfrastructures and utilities. While there is a lawthat empowers government to recover such unearned increment in land values, this law (seeSections 47-55, Chapter V of PO 464) has notbeen implemented. Again, there must always bea first time.

The present study was mainly concernedwith direct threshold costs. There are however,several other costs that may be significant insome cases and should be analyzed in futureapplications if found to be necessary, namely:cost of frozen assets; running or exploitationcosts; normal costs and grade threshold costs.For instance, inclusion of some major normalcost causing variables if a detailed topographyof the grouping is available may result in possible layouting of the internal streets and services(not necessarily grid method) and consequentlybetter comparison between different groupingsand better understanding of neighborhood layouts can be obtained.

On the whole, the results of this study willgo a long way towards the realization of SanPablo City as one of the growth centers identified in various regional studies to catch MetroManila's overspill population and other ruralto-urban migrants. In a broader sense, however,this study has sought to enrich urban planningpractice in the Philippines. It has simplydemonstrated that decisions regarding theshape, intensity and direction of future urbanexpansion need not be based on arbitrary andintuitive considerations but on rational, objective and, to the extent possible, quantitativeones.

THE USE OF THEMATIC MAPSIN ANALYZING SOIL EROSION SUSCEPTIBILITY

OF THE PHILIPPINES

ROMEO C. BRUCEProfessor

Training Center for Applied Geodesyand Photogrammetry

UP College of Engineering

INTRODUCTION

Soil erosion has long been recognized as amajor hindrance to increased agricultural production in many areas in the Philippines.Awareness and knowledge of the extent of soilerosion are essential in planning the development of an area, especially if the activities tobe undertaken will have great impact on theecological balance of the community. One ofthe problems facing environmental managersand planners is the lack of reliable informationregarding the extent and spatial distribution ofsoil erosion in the Philippines.

The principal objective of this paper is todetermine the extent of different classes ofsoil erosion susceptibility in several provincesof the Philippines by the analyses of existingthematic maps such as land use maps, soilmaps, slope maps and rainfall maps. The goalwas to study all provinces particularly in placeswhere physical and environmental conditionsmay heiqhten soil erosion. Results in fifteen(15) provinces are presented in this paper.

Overview ofSoil Loss in the Philippines

Soil loss is occurring all over the Philippines.At the mouth of every river, large or small,there is a fresh and increasing delta of top soilwashed off the hillsides and lands upstreams.The critical loss of Philippine watersheds isalarming. Of more than 400 principal water-

22

sheds, over half of these can be classified ascritlcal.!

Practically all the lands suitable for agriculture are already farmed. Any proposal forintensifying agricultural development will mostlikely be toward increased efficiency in management of land already in cultivation rather thanthe expansion in the utilization of marginallands. Data on changing land use will show thatthe growth of cities is a leading source of cropland loss in the Philippines.2

There is an urgent need to determine theextent and distribution of soil erosion and toidentify highly susceptible areas into whichappropriate preventive and rehabilitation measures could be introduced.

Basic Concepts of Soil Erosion

Soil erosion involves detachment, transportation and deposition of soil by water and windaction. The principal agent of transporting soilin the Philippines is water. The four factors

lR.C. Bruce, Principal River Basins of the Philippines. National Water Resources Council Report No.4, October, 1976,82 pp.

2----, "Soil Erosion Guidelines on Urban

Lands," Philippine Engineering Journal, Vol. 3(2),December 1982, National Engineering Center, U.P.l"'i1iman.

-affecting soil erosion in Philippine landscapeare: (1) land use, (2) soil type, (3) slope, and(4) rainfall characteristics.

Land Useasa Factor of Soil Erosion

Flood destroys millions of pesos worth ofpublic and private properties and causes deathand untold misery. In the Philippines this destructive force is often attributed to forest overlogging, kaingin clearing, improper managementof agricultural lands especially in sloping areasand other soil·disturbing activities of man suchas building settlements, installing infrastructureand preparing sites for industries.

The type of crop raised is also an importantfactor that determines the degree of soil erosionover cultivated areas: Observations consistentlyshow that in places with similar slopes, theamount of surface runoff from row crops suchas corn and upland rice is considerably higherthan in the fields planted to coconut and othertree crops (especially if the ground is denselycovered with grasses). So long as the land isdensely covered with vegetation, soil type inthe farm does not significanlty affect theamount of surface runoff. All soils possesscertain resistibility to erosion, and this resistibility may be increased greatly by vegetalcover. The subsoil may have less resistibilityto erosion, and, if the surface condition ischanged by cultivation as to destroy the resistance of surface soil, erosion will begin on landwhich was not subjected to erosion before.

In the Philippines, natural cover, if allowedto develop, effectively protects, the soil. Consequently, disturbance and removal of coverthrough change of land use must be accordedhigher priority in evaluating soil erosion problems and in selecting erosion control practicesin the country.

Soil asa Factor ofSoil Erosion

A number of properties of soils and theirinteraction contribute to the susceptibility ofthe land to soil erosion. Soil texture, depth,permeability, structure, presence of impermeable layer and organic matter content aresignificant factors affecting soil erosion. Per·meability of the soil is a main factor affectingrunoff and erosion. The depth of soil fromsurface to the least permeable layer affectsthe permeability. Rainfall in excess of theamount needed to saturate the' soil above

23


the impermeable layer would run off theground surface and carry with it soil from unprotected sloping areas.

Depth of solum (topsoil and subsoil) is avery important factor in measuring the susceptibility of the land to soil erosion. Betweentwo kinds of soil with similar texture, the one

'with thinner solum will likely be more susceptible to soil erosion. Areas with looseshallow top soil underlaid with dense subsoil oflow permeability are vulnerable to serious soilerosion. In the gully, once the water has cut""'eresistant subsoil down into a loose or soft layerof underlying material, the caving-in that resultshastens truncation of the soil profile.

Slopeasa Factor of Soil Erosion

Slope is the inclination of the ground surface with respect to its horizontal distance. Itis expressed in percent slope which is the rise ofthe land for every 100 meters horizontal distance. The characteristics of slope influencingsoil erosion are the degree of slope and thelength of slope. The steeper the slope, otherfactors being the same, the greater the velocityof the surface runoff. The length of the slopeis significantly important since the greater theextension of the inclined area, the greater isthe concentration of the flooding water. Thelower end of the slope is more seriously affected than the upper end of the slope.

Rainfall asa Factor of Soil Erosion

High intensity and amount of rainfall contribute greatly to the problem of soil erosion inthe Philippines. In some parts of the countrythe average annual rainfall reaches to as high as3.5 meters. The intensity of rainfall in thePhilippines is alarmingly high. Records showthat Baguio City experienced 1.5 meters ofrainfall per day in 1911.

Rainfall is characterized according to intensity, duration, distribution, total amount andrain-drop size. It is possible to predict theextent of soil erosion by knowing two or moreof these characteristics. A high intensity rainfallwhich lasts for a long duration will bring aboutserious soil erosion. The more frequent the rainthe more chances will there be of soil erosionbecause once the soil is saturated the excesswater will occur as surface runoff. Long,heavy -downpour is more erosion-promotingthan light rains because great runoff results.


The soil can absorb only so much water for agiven length of time and whatever rainfall isadded in excess of the absorbing capacity ofthe soils results in more surface runoff. Aftermany days of rainfall, the soils will becomesaturated with water and will no longer becapable of absorbing any additional rainwater.At this period all vegetation, including litterson the ground, are saturated. Any amount ofrain falling during this time will only becomerunoff and will cause soil erosion.

Methods of Determining Soil Erosion

In assessing soil erosion, two procedurescan be followed. The first involves direct observation and measurement. The degree of soilerosion for a given area is judged by the extentto which the original surface soil has been removed through erosion. This is estimated by acomparison between the present depth of soilprofiles and the depth of comparable virginprofiles of the same type under similar topographic conditions. In cases where the virginsurface is shallower, the lower part of the solummay be used in estimating the degree of soilerosion.

The second method of soil erosion hasbeen adopted by the Bureau of Forest Development in the absence of profile investigation.The system relies heavily on the type of groundcover and the slope of the land. Other factorslike soils and rainfall are not considered.

With measurements over a long period oftime it is possible to determine the erodibilit~

of the soil and express it in quantitative terms.Sufficient laboratory and field experimentaldata are needed. Obtaining these require longyears of research and considerable amount ofmoney and manpower.

Soil Erosion Susceptibility

Direct observations of soil erosion is virtually not available in the Philippines.4 However, it

3R.J . Loch & Freebain D.M., "Methods forMeasuring Soil Erosions," Soil Erosion Management,ACIAR Proc. series No.6, 1984. Phil. Council forAgriculture and Resources Research and Development,

pp.57-63.

4R.C. Bruce," Assessment of Some Erosion Prediction Models for Applications to the Philippines," SoilErosion Management, ACIAR Proc. Series No.6,PCARRD, pp, 42-49.

24

is possible to arrive at an expression of soilerosion susceptibility by interpreting variousthematic maps: land use, soil, slope and rainfallmaps, singly and interactively as factors of soilerosion.

Soil erosion susceptibility is a land qualitythat results from the interaction of land use,soil, slope and rainfall characteristics. It is thesusceptibility of the soil to particle detachmentby rainfall and runoff. The degree of soil erosion susceptibility is not quantified because ofthe absence of laboratory and experimentaldata. The classification is purely in relativeterms as it refers to the potential soil loss froma particular land, based on interactive effects ofland use, soil, slope and rainfall characteristics.

The delineation of areaswith different classesof soil erosion susceptibility was accomplishedusing the "covergence approach".S The procedure is to transform the thematic maps (landuse, soil, slope and rainfall maps) into a singlefactor soil erosion susceptibility map for landuse, soil, slope and rainfall, with a commonscale of 1:250,000. The single-factor mapshows only the areas delineated as highly susceptible to soil erosion.

Single-Factor Soil Erosion Susceptibility Map

The thematic maps were transformed into asingle-factor map that shows only the areas thatare highly susceptible to soil erosion.

Land Use as Single-Factor Map

Areas covered with the following land usetypes were delineated as highly susceptibleto soil eroston:"

1. Marginal agricultural land2. Pasture/grassland3. Denuded forest land

SR.C. Bruce, "Eco-Engineering Analysis for LandUse Planning," Philippine Planning Journal. Vol. 12(2). Institute of Environmental Planning, University ofthe Philippines, Diliman, Quezon City.

6Ministry of Human Settlements, Regional LandUse Map, Scale 1:250,000.1980. Unpublished.


Themat~c Map

8j~Land Use

~~Soil

[2]Qrr

Rain a

H1&hly Susceptihle:Land Use

Highly Susceptible:Soil

Highly Susceptible:Slope

Highly Susceptible:Rainfall

4-factorSoil Er os Lon

susccr-t i b i lI t;,!-jclP

Fig. 1 Single-Factor Soil Erosion Susceptibility Map(Hatched Area)

Schematic diagram of thematic maps. transformed to soil erosion susceptibility map and superimposed over _ another to produce the four-factor soil erosion susceptibility map. Explanation: Land use+ r-rk:e paddy. c-coconut.p-pasture; Soil + 1-deep clay loam. 2-shallow sandy loam. 3-shall_ silt loam; SIo~ + a-o-3% slope, d-18-30% slope,e-greater than 30% slope; Rainfall + I - More than 2 dry months, 5-9 wet months; 1/ - 2-4 dry mont", 3-4 wet monthsDry month is when the rainfall is less than 100 mm per month and wet month is when the rainfall is more than 200 mmper month. Four-factor soil erosion susceptibility map; - '-not susceptible to soil erosion; 2-s1ightly susceptible to soilerosion. 2-factors converges (slope and rainfalll; 3a - moderately susceptible, 3 factors converged (land use, soil andslope); 3b - moderately susceptible, 3 factors converged (soil, slope and rainfall); 4 - highly susceptible, 4 factorsconverged; 5 - highly susceptible due to rainfall only; 6-highly susceptible to land use factor only.

Soil as Single-Factor Map

Considered to be highly susceptible toerosion are the following soils: '

1. Soils with less than 50 cm. sotum; lessthan 40% clav-sllt fraction. This category includes all fine sands and sandyloains.

2. Soils with less than 50 cm. solum;40-60% clay-silt fraction. This groupincludes all silt loams, sandy clayloams, and silty clay loams.

3. Unclassified soils in the mountains.

'R.C. Bruce, Soil Map of the Philippines based onDepth of Solum and ClaY-Silt Content of Surface Soil.Scale 1:250,000. TCAGP. University of the Philippines, Diliman, Quezon City. Unpublished.

25

Slope as Single-Factor MapLands with the following steepness of

slope were classified as highly susceptibleto soil erosion: 8

1. Steeply sloping and steeply rollingland, 18-30% slope.

2. Hilly and mountainous land, 30% ormore slope.

Rainfall as Single-Factor MapAreas with the following rainfall charac

teristics were considered highly susceptibleto erosion: 9

8---- -, Regional Slope Map of the Philip-

pines. Scale 1:250.000. Land Use Planning UnderDifferent Agroclimatic Environment. InternationalFood Policy Research Institute IIFPRII and AsianDevelopment Bank (ADB) Research Paper. 1984.

9/ RR1, Agroclimatic Map of the Philippines, International Rice Research Institute. 1979.

llocos SurIloiloLa UnionMasbateMarinduqueZambalesZamboanga


1. Areas with less than 2 dry months, and5-9 wet months.

2. Areas with 2-4 dry months, and 7-9wet months.



5. All areas with one or more monthswith 500 mm or more per month ofrain.

Classes of Soil Erosion Susceptibility

The single-factor soil erosion susceptibilitymaps with a common scale of 1:150,000 wereprinted on transparent overlays. When superimposed over one' another, a converged areafor 4.3 and 2 factors appear and become thebasis of soil erosion susceptibility classes asfollows:

1. Areas highly susceptible to soil erosion:where 4 factors converged;

2. Areas moderately susceptible to soilerosion: where 3 factors converged;

3. Areas slightly susceptible to soil erosion:where 2 factors coverged.

Figure 1 shows the schematic diagram ofthe four thematic maps, transformed to soilerosion susceptibility maps and superimposedover one another to produce the final soilerosion susceptibility map. This map showsareas susceptible to soil erosion on the basisof the combined effects of four factors of soilerosion: land use, soil, slope and rainfall characteristics.

When overlaid with one another, the singlefactor soil erosion susceptibility maps show theareas with susceptibilities ranging from none tohighly susceptible depending on the number offactors shown on the converged portion. Areadesignated as 1 in the final 4-factor soil erosionsusceptibility map is not susceptible to erosionbecause of the favorable condition of each ofthe four factors. Where two factors convergedthe area is classified as slightly susceptible tosoil erosion. It could be a combination of anytwo factors. The area where any three of thefour factors converged is identified as areawhich is moderately susceptible to soil erosion.Where all four factors converged the area isclassified as highly susceptible to soil erosion.

Residual area of one-factor is classified assusceptible to soil erosion due to the unfavor-

26

ableness of that' factor. Areas 5 and 6 are classified as areas susceptible to soil erosion due respectively to rainfall and land use only. In thestudy of 15 provinces, areas 1, 5 and 6 in thefinal four-factor soil erosion susceptibility mapare included in the area classified as slightlysusceptible to soil erosion.

Soil Erosion Susceptibility of SelectedProvinces

Soil erosion is the most serious form of landdegradation in the Philippines. While the soilscientists, engineers, agronomists, farmers andthe public in general acknowledge that soilerosion is serious in the country, no analyticalor systematic study has been undertaken todocument the problem, its consequences, orpotential solutions. This simplified method ofdetermining the soil erosion susceptibility willbe of great value for proper land use planningof the provinces, particularly in the utilizationof hilly regions of the country. Due to thepopulation explosion and food shortages,hilly regions will be cultivated more and morein the near future. Measures must be undertaken by the government to combat the landmisuse problem. Delineation of areas intovarious classes of soil erosion susceptibility willhelp planners in formulating a land allocationpolicy for the Philippines.

The methodology of determining the susceptibility of the area to soil erosion was utilizedin fifteen (15) provinces of the Philippines, asfollows:

AbraAntiqueBatangasBoholCapizCebuCotabatoDavao

Each province was studied, classified andmapped according to the following soil erosionsusceptibility classes:

1. Areas highly susceptible to soil erosion2. Areas moderately susceptible to soil

erosion3. Areas slightly susceptible to soil erosion' °

lOlncludes also areas classified as "not susceptible"and areas classified as "susceptible" to soil erosiondue toone factor only.

The factor which has overriding effect onthe susceptibility of the soil erosion was determined for each province. This is indicated bythe single-factor effect on soil erosion susceptibility of the land. The single-factor thatplaced the biggest hectarage of land to a category of highly susceptible to soil erosion wasconsidered the overriding factor of soil erosionsusceptibility in the province.

Results of Soil Erosion Susceptibility Study

Table 1 shows the area in each of the provinces with different classes of soil erosionsusceptibility. The overriding factor of soilerosion susceptibility is also indicated.

In eight of the fifteen provinces, rainfall wasthe overriding factor of soil erosion susceptibility. Contrary to what has been claimed bymany workers, slope is not the principal factorof soil erosion susceptibility. Abra and Zamboanga were the only two provinces whereslope was found to be' the overriding factor.Soil type as an important soil erosion susceptibility factor was true only in the province ofCotabato.

Results of the study show that a combination of high amount of rainfall and land usetype that provide less or no cover to the soilmakes the land highly susceptible to erosion.


Changes inland use greatly affect the susceptibility of the soil to erosion., Vegetativecover is the most important factor affectingthe initial resistance of soils to erosion. Vegetative cover breaks the force of rain drops,thereby reducing the effects of- the energy offalling rain in breaking down the crumb structure of the soil and packing the surface soil.As long as the soil is covered with vegetation,soil erosion is minimal even on moderatelysloping land.

Limitations of the Methodology

This method of determining the susceptibility of the land to soil erosion is by no meanswithout limitations. The thematic maps utilizedwere not evaluated in terms of their accuracy.Rainfall intensity, although a very significantfactor of soil erosion, was not considered.There are other important factors of soilerosion that were not considered because ofthe absence of information from thematic mapsused. These include characteristics of soil profile, density of vegetation, length of slope andthe geology of the region. The methodologyneeds a number of refinements and evaluationof the results must be done for modificationand inclusion of other factors of soil erosionsusceptibility.

TABLE 1. Hectarages of Soil Erosion Susceptibility Classesfof Selected Provinces in the PhiJippines*

-----------------------------------------------------------------~---------

Land Area Highly % Moderately % Slightly % Overriding FactorProvince (ha.J Susceptibly Susceptible Susceptible

-----------------------------------------------------------------------------ABRA 397.555 29.700 7 333.655 84 34.200 9 Slope. land use

ANTIQUE 252,251 57,600 23 97,626 39 96,975 38 Rainfall, soil

BATANGAS 316.586 177.288 56 15.830 5 123,468 39 Land use. slope

BOHOl 411.772 46.800 12 364.926 88 land use. soil

CAPIZ 263.317 84.600 32 178.717 68 Rainfall. slope

CEBU 508.939 437.687 86 30.536 6 40.716 8 Land use. slope

COTABATO 2.379.705 445.950 19 1.933.755 81 Soil. slope

DAVAO 1,459.580 134.100 7 1.102.280 66 730.800 37 Rainfall. slope

IlOCOS SUR 257.958 29,075 11 102.825 40 125.883 49 Rainfall. land use

ILOILO 532.397 43,425 8 139.275 26 349.697 66 Rainfall. land use

LA UNION 149.309 71.668 48 26.876 18 50.765 34 land use. rainfall

MASBATE 404.769 27.900 7 376.869 93 Rainfall. land use

MARINDUQUE 95.926, 68.813 72 27.112 28 Rainfall. land use

ZAMBAlES 371 ,440 14.360 4 174.340 47 182.700 49 Rainfall. slope

ZAMBOANGA 1.599.730 31.500 2 1,136.230 71 432.000 27 Slope. rainfall

-----------------------------------------~-----------------------------------------------------------------------------------------------------------------,.'No provincial subdivisions was made for Cotabato, Davao and Zamboanga. Percent (%) indicate the percent of the total land

area of the provinces.

27 . ~


There is need for research on the effect ofeach of the four factors on actual soil erosion.For example, what types of land use is moresoil erosive under:

a. certain steepness of slopeb. particular types of soil, andc. certain rainfall characteristics

CONCLUSION

The methodology is applicable in rapidassessment of all provinces in terms of the sus-

ceptibility of the land to soil erosion. The useof recent aerial photo coverage and LANDSATimagery will increase the delineation accuracyof soil erosion-prone portions of the provincebecause land use type and topographic characteristics can be determined with high degreeof accuracy. Spatial distribution of susceptibleareas can be precisely drawn with the use ofaerial photographs. In many provinces intensityof rainfall can be estimated to improve the rainfall data input in the system.

28

PROBLEMS OF DEVELOPING A LOCALLAND POLICY: THE CASE OF SANTA ROSA

Tito C. FirmalinoProfessor

School of Urban and Regional PlanningUniversity of the Philippines

POPULATION GROWTH IN THEPERIPHERY OF METROPOLITAN MANILA

Most municipalities experiencing rapid population increases are faced with the huge problem of coping with the demands of the newcomers. The demands may take the forms ofadditional job opportunities, an improved system of waste disposal, provision of essentialsocial services and facilities, and many otherequally urgent needs. These needs generallyrequire land as a physical base or site for building structures, communities, facilities andhuman actlvltles. Often vast areas of rich agricultural land are converted into urban uses toaccommodate the requirements of the urbanpopulation.

Municipalities that suffer most the heavypressure of converting agricultural land to otheruses are the municipalities at the periphery offast growing metropolitan areas. These municipalities attract households from the metropolitan core cities and municipalities who moveto suburban places in search of residential unitswhich they can eventually own.

The process of suburbanization, characterized by the flow of population from metropolitan areas to SUburban municipalities, is veryevident in Metropolitan Manila. As shown inthe national census data of 1980, the munlcipa

lities close to Metropolitan Manila were amongthose which recorded the highest percentageof population increase over the 1975 censusfigures. For instance, the municipalities of SanPedro, Santa Rosa, and Cabuyao in the province of Laguna, had population increases of71 .63 percent, 35.03 percent, and 26.75 percent,respectively. These are municipalities next toMetropolitan Manila toward Southern Luzon.The towns of Bulacan near Metropolitan Manila that registered equally high rates of population increase during that period are Marilao(66.86 percent), Meycauayan (38.78 percent),and San Jose del Monte (53.73 percent). Bacoor in Cavite had 45.22 percent increase. Thepopulation of Dasmarjfias, also in Cavite,jumped by 127.56 percent, but Dasrnarifiashadbeen the relocation area of Metropolitan Manila squatters. In Rizal province, Antipolo had anincrease of 68.31 percent, Cavite had 59.65percent and Anyono had 51.19 percent.

The population increase of the city of Manila during the period studied was only 10.23percent. Pasav's population grew by 12.85 percent, that of Quezon City by 21.84 percent,Caloocan City by 17.78 percent, Makati by11.42 percent, M.,labon by 9.22 percent, andSan Juan by 6.20 percent. These are the citiesand municipalities at the core of MetropolitanManila. In contrast to the municipalities at the


periphery, the political units at the Metropolitan core had insignificant increases indicatingout-migration of the population to suburbansettlements. The small gains in populationof the mentioned cities and municipalitiescould be attributed to natural increase and toimmigration from distant rural communities.

Industries were also pushed to suburbanlocations by high population densities, trafficcongestion and high land values or rentals inthe inner portion of Metropolitan Manila.!Besides, heavy industries are discouraged fromlocating within the 50 kilometer radius fromthe City of Manila. 2 From a study by theNational Economic Development Authority(NEDA) Region IV office, the following werefound to be the most influential factors thatforced industries to move to suburban towns:1) low cost of labor; 2) availability of sufficientwater; 3) good transportation; 4) availabilityof reasonably-priced industrial sites; 5) relativeease of disposing factory effluents; 6) nearnessto large potential markets; 7) pleasant livingcondition in the area; 8) availability of low costraw materials; and 9) greater potential for economic growth.

THE NEED FOR EFFECTIVE LAND POLICY

From the discussion above, it becomes clearthat the municipalities at the fringes of Metropolitan Manila need to anticipate the problemsthat may arise due to population overspill fromthe metropolitan area. Each unit of governmentshould adopt a land policy to guide the physicalexpansion of the town to prevent haphazardand uncontrolled growth and, perhaps, overcrowding in the future. Rapid increase in population without new sources of revenue to sup-

ICited in Towards Regeneration and Redevelopment of Manila, an unpublished report of The BusinessResearch Center, Makati, February, 1985.

2Memorandum Circular issued by the Office ofthePresident on December 17, .1973 instructed the'Human Settlements Commission to see to it' that"there shall be no more factortes, plants, industriesand the like to be established within a 50-kilometerradius of Manila."

30

port the requirements of the newcomers canput unnecessary strain on the existing facilitiesand resources of the receiving town.

A sound land policy can direct developmentto a desired locatien. It certainly has to beanchored on the land use plan which embodiesthe aspirations and hopes of the residents. Theland use plan can establish the scale of urbanexpansion realizable within a specified period,judged on the local government capacity toabsorb the cost.

In the land use plan, the residents can settheir objectives regarding the character of theenvironment they prefer. How fast should themunicipality grow? What areas should be conserved to maintain the natural systems? Whatshould be the role of the municipality in theprovince or region to which it belongs?Through proper implementation of the land useplan, urban sprawl can be contained and incompatible land uses minimized.

Based on the above, the fQlioWing questionsarise: Are the local officials conscious of theenvironmental problems that will emerge ifthe municipal government is unprepared toaccommodate changes in population densities?Are there measures taken to preclude or minimize the effects of the threatening problems?Have the local officials initiated the formulation of policies to provide the direction of thegrowth of their communities? To seek theanswers to these questions, a study was made ofSanta Rosa town in Laguna Province during thelatter part of 1985.

The main objective of the study was to obtain insights into the awareness of the municipal officials of the 'importance of the landuse plan or land management to promote theattainment of the environment they desired.The study could also reveal the techniques usedin implementing tha land use plan as well asthe nature of policy adopted to guide the physical development of the town.

Data were gathered through interviews withthe local officials, representatives of nationalagencies, and developers. Analysis was alsomade of the comprehensive plan and otherreports filed in the planning coordinator'soffice. The minutes of the Sangguniang Bavan(local legislative body) from 1980 to 1985

were examined to seek Inforrnatlon on policystatements, resolutions and ordinances relatedto land and to the development of the town.

PHYSICAL AND DEMOGRAPHICCHARACTERISTICS OF SANTA ROSA

Santa Rosa is about 40 kilometers from theCity of Manila and is accessible from the metropolitan area through the old national highway.The new Manila South Expressway passes therural portion of the town but no exit route toSanta Rosa was provided.

The jeepneys serve the transport need ofthe residents whose destinations are the nearbytowns of Laguna and Cavite. The Biiian-Calamba route which passes Santa Rosa and Cabuyaohad more than 700 passenger jeepneys in operation in 1983 and the number could have goneup considerably since then.

Feeder roads connect the 15 barangays orvillages of Santa Rosa and the pob/acion astown center. Three barangays comprise thepob/acion, making the total number of barangays to eighteen. The residents in barangaysuse tricycles in commuting to the pob/acionwhere the public market, municipal hall, shops,'clinics, and offices are located.

Vast areas are still devoted to agriculture. Ofthe total area of 5,415 hectares, only 580 hectares (10.71 percent) comprised the built-upportion in 1983. Some 4,793 hectares (88.51percent) were planted to crops and fruit trees.

The land is level and fertile. The slope rarelyrises above 2.5 percent. There is sufficientground and surface water for irrigation. Themajor crops are palay, sugarcane and vegetables.The sugar cane fields are in Pulong Sta. Cruz,Sto. Domingo, and Don Jose, the three biggestbarangays of Santa Rosa in terms of area. Mostof the sugarcane fields belong to the CanlubangSugar Estate.

The total population of Santa Rosa in 1980was 64.325. This was 35.03 percent higherthan the 1975 population of 47.639. In thatyear (1980) Santa Rosa ranked fifth in population among the towns of Laguna. Its pob/acionhad 13.4 (or 8,618) percent of the town'spopulation resulting in a density of 157 personsper hectare, the highest among the barangays.

31

PH/LIPP/NE PLANN/NG JOURNAL

The pob/acion is the center of activities andhas mixed land uses. The residential areasusually follow a linear pattern with housesfronting the old national highway while behindthe buildings are ricefields. Many of the residences perform other functions. They providespace for offices and commercial establishments.

BaJibago, a barangay situated near the southern end of the town, functions as a subcenterwhere a private market conveniently cater tothe shopping needs of the residents of the surrounding barangays. A few industries are inoperation in Balibago.

Several residents work outside the town.One can notice a huge number of commutersboarding vehicles for Metropolitan Manila inthe early morning of any ordinary working day.

THE LAND USE PLAN OFSANTA ROSA

The town of Santa Rosa has a comprehensive development plan prepared in 1980 withthe assistance of a team of planners from theHuman Settlements Regulatory Commission(HSRC) and the Laguna Lake DevelopmentAuthority (LLDA). An essential componentof the plan was a land use scheme which statedthe role of the town in the development of theSouthern Tagalog Region as a member of the"multi-functional urban nucleation" to absorbpopulation overspill from Metropolitan Manila.The other towns were San Pedro, Biiian andCabuyao in Laguna and Carmona in Cavite. Thetype of development preferred was a compactone which would try to consolidate the looselysettled areas and thereby avoid sprawl.

The scheme divided the town into zoneswhich were to expand gradually. A specificland area was allocated to allow the expansionof each. The principal objective for the residential areas was to achieve a pleasant, safe, andhealthy environment. The approach was toform neighborhood units which would be provided with vital community facilities andservices.

Identified as the main commercial zone wasthe central business district which was in thepob/acion. A small commercial center in Balibago .. was proposed for development as supplement to the business district in the pob/scion.


1510

@• CITY

o _ICIPAL

_ NATIONAL ROllO

_ PROVIIlClAL ROAD

~RAILROAD

LEGEND:

ICILOIIETERS

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MAP: STUDY AREA (SANTA ROSA) AND METRO MANLA

32

Institutional and recreational areas were, likewise, in the poblacion where, at prese~t, thehealth center, scouting office, gymnasium,basketball and tennis courts, parade ground,police headquarters, children's playground andmajority of the institutional offices are found.Accessibility from all sectors was the importantfactor why the poblacion was assigned thesefunctions.

The sites of existing large industries were tobe maintained as industrial zones. Only lightand medium-scale industries which did notproduce nuisance were welcome. Nuisance, ofcourse, referred to the discharge of excessivesmoke and other harmful effluents, the trafficproblems generated due to the movement ofheavy trucks, and many other disturbancesinherent in the operation of heavy industries.

Proposed industrial sites were in Pulong Sta.Cruz, along the national highway towardsCavite, Dita, near the boundary of Santa Rosaand Gabuyao, and Tagapo along the provincialroad at the boundary of Bifian and Santa Rosa.The factors considered in selecting the siteswere: 1) some industries were already there;2) the land was non-irrigated, generally plantedwith sugar; 3) the proposed sites were alongmajor highways, and 4) they were far from thepoblacion.

Agro-industrial activities were to be encouraged by providing infrastructure support suchas feeder roads, water supply and power. Although power and water supply were available,these were not under the responsibility of themunicipal government. Placed in the categoryof agro-industries were livestock, poultry,piggery, and duck-raising.

Also stressed in the land use plan was theproper conservation and optimum utilization ofprime agricultural areas. As much as practicable, conversion of high-yielding agriCUlturalland into urban uses should be prevented.

POLICY AREAS

A clearly defined land po/icy respected bythe decision-makers and the people will facilitate the implementation of the land use plan.There are factors that will ensure the effectiveness of the policy to which the alert municipal

33


officials should focus their attention. One is theavailability of resources to carry its implementation. Another is the capability of the organization (assigned with the responsibility of executing it) to translate the policy into action. Thethird is the Willingness of the citizens to support it.

By examining the Local Government Code,one can find the areas upon which the land policy can be based. It is understood that theformulation of any policy at the municipallevel is the prerogative of the SangguniangBayan. Section 149 of the Code enumeratesthe powers and duties of the SangguniangBayan and among them are powers related tothe control or influence over the developmentof land, whether it is government- or privatelyowned.

Some of these powers are concerned withthe control and regulation of the use of property, maintenance of utilities, establishmentof infrastructure facilities, construction ofroads and bridges, adoption of measures toprotect the public from floods, fire and othercalamities, and abatement of nulsance.

The type of p.olicy that can be promulgatedmay represent any or a combination of thefollowing: 3

1. A policy that will directly control or regulate the development of land (e.g.zoning and other kinds of regulation);

2. A policy that touches on the expenditureof municipal funds (e.g. acquisition ofland by the municipal government forfuture use or for conservation, government operation of services, and expenditure on infrastructure); and

3. A policy that can influence private actionon land through use of incentives (e.g.offering cheaper sites to industries, pro-

31n his investigation of land policies around theworld, Nathaniel lichfield found three major categories of land policy: 1) direct control of development, 2) fiscal control over development, and 3)general influence over development. c.f. NathanielLichfield, Settlement Planning and DevelapmlllJt: AStrategy for Land Policy. (Vancouver; University ofBritish Columbia, 1980), p, 32.


viding utiiities to reduce cost of development, and eliciting support to conservetion measures).

IS THERE A LAND POLICY INSANTA ROSA?

The best source of information about theland policy (if one existed) in Santa Rosawould be the minutes of the SangguniangSayan. A study of the minutes over a periodof five years (1980 to 1985) was thereforemade. The resolutions and ordinances enactedand the discussions of the Sangguniang Sayanon various matters affecting land were investigated. The search for the policy proved to bea very frustrating exercise. As Philip M. Raupobserved, "Our policies have failed us, not inthe sense .that they were wrong, but in thesense that they were non-existent"." Thisstatement aptly applies to Santa Rosa.

Certain policy statements could be extractedfrom the zoning ordinance enacted on August26,1981, but these were quite general in nature.For example, a statement was made about landas a limited resource and, therefore, should bemanaged for public welfare rather than as acommodity of trade subject to price speculation.

There were attempts to develop a coherentpolicy but the Sangguniang Sayan memberswere confronted with difficulties, some ofwhich were beyond their powers to resolve.Besides, developing a land policy was still farfrom their thinking until in 1985, when somemembers of the Sangguniang Sayan expressedconcern over the dwindling agricultural landsdue to their conversion to subdivisions or urbanuses. It was the feeling of the kagawads ormembers that the growth of population wouldincrease the demand for production of agricultural crops. As a result, Ordinance No. 8 waspassed on March 13, 1985 providing that anylandowner who desired to convert his agricul-

4See Philip M. Raup, "Urban Threats to RuralLands: Background and Beginnings," in the AmericanInstitute of Planners, November 1975, p. 377.

34

tural property into industrial use should be required. to obtain permit from the municipalgovernment.

This ordinance saw its enforcement in thecase of Fabercon Builders Incorporated, late in1985, when it applied for the conversion of apiece of agricultural land in Salibago into ahousing subdivision and, at the same time, requested the munipality to lease (for ten years)a municipal road at P1,OOO annually as accessto the proposed subdivision. All the kagawadsvoted against the application with one citingthe need to produce food as the first prioritywhile housing was only second. It was alsonoted that many subdivisions had been openedresulting in the massive reduction of agricultural hectarage. Another .Sangguniang Sayanmember reminded his fellow kagawads thatthere was an organization which wanted theconversion of its agricultural land to anotheruse but which was not granted. At this stage,it seemed that a policy on land developmentwas emerging but, as stated earlier, the municipal officials were burdened with major difficulties, among which were the following:

A. Pervasive Control Over LandDevelopment of Higher Authorities

Sometime in 1980, the municipal government of Santa Rosa tried to establish controlover the development of the lakeside. A fewbarangays were at the edge of Laguna de Bayand fishing and duck raising were two principaloccupations of the residents in these barangays.The Sangguniang Sayan enacted Ordinance 12which amended Ordinance No. 10 of 1974,providing among others the "zonification ofmunicipal waters for ... delineation of areasallowable for fishing purposes." A distance of50 meters between reservations had to bemaintained for free navigation and fishing wasnot allowed "within 200 meters from a fishcoral licensed by the municipality." Again, in1981, a Sangguniang Sayan member suggestedin the Sangguniang Sayan's session that a ceiling of P50,OOO capitalization be imposed sothat the big capitalists would not endanger thelivelihood of small duck raisers.

Unfortunately for the town, LLDA, anational agency empowered "to conserve and

develop the resources of the Laguna de Bayregion" exerted its rights to issue the permitas provided for in PD 813 of 1975. Accordingto the decree, one of the special powers of theLLDA was "to pass upon and approve or disapprove all plans, programs, and projects"proposed by the local government, publiccorporations and private persons or enterprisesif such plans, programs and projects were related to those of the Authority.

What the municipality did was to pass Resolution No. 30 on August 11, 1982, requestingLLDA to first refer to the municipal mayor allapplications received by the Authority forinstallation of fish pens over portions of thelake which were within the territorial jurisdiction of the town before taking action. Themove was intended to protect the small fishermen of Santa Rosa.

The implementation of the zoning ordinance. was not purely a local responsibility. In fact,the zoning ordinance of Santa Rosa, althoughadopted by the Sangguniang Bayan, was a version drawn up by the Human SettlementsRegulatory Commission (HSRCl. Letter ofInstruction 729 of 1978 had assigned the powerto issue development permits to the Ministryof Human Settlements and this power wasexercised by HSRC. In turn, a zoning administrator appointed by the municipal governmentwas deputized by HSRC to implement theordinance. A complicated situation thereforeexisted where the land use plan was preparedby the municipality and the zoning ordinanceenacted by the Sangguniang Bayan as an irnplementing tool was enforced by HSRC,through the deputized zoning administrator,who was an employee of the municipal government.

Ordinarily, the zoning administrator issuedlocational clearance for certain uses. Appealsto his decisions were forwarded to the regionaloffice of HSRC for final action. Applicationsfor other types of development were referredto HSRC. Among these were dumping sites,incinerator plants, cemeteries, filling stations,cockpits, highly pollutive and hazardous industries, public markets, slaughterhouses, subdivisions, projects of national significance, projects categorized as environmentally critical,

35


and development of environmentally criticalareas. Issuance of permits for a number of thementioned projects could easily be handled bythe municipal government.

The subdivision plans of developers in SantaRosa were approved by HSRC without firstbeing referred to the municipal government.The zoning administrator was bypassed. Froman interview with the municipal mayor, it wasgathered that as soon as the plan was approvedby HSRC the developer approached the municipal officials for the issuance of buildinq permits. It was only then that the officials cameto know of the subdivision project which hadalready been approved.

As ?f 1986, there were 52 housing subdivisions with a total area of about 207.35 hectares.Some developers sold lots only and the buyersgenerally purchased them for speculation.Other developers constructed houses and soldboth lots and houses to buyers .

The conversion of agricultural areas intosubdivisions resulted in wastage of resourcessince lots without houses built on them reomained idle and unproductive. Large tracts ofagricultural land serviced by irrigation systems(operated by the National Irrigation Administration) had been converted into subdivisions.For instance, between 1984 and 1986, a lossto urban expansion of approximately 44 hectares of irrigated agricultural land was recordedby the National Irrigation Administration.

It was difficult, however, to retain the landfor agricultural use, according to the municipalagriculturist. The subdivision developers offeredattractive prices for the land which the landowners could not resist. Even tenanted lots, theconversion of which was controlled by the Ministry of Agrarian Reform, were taken out ofcultivation. The landowners were able to findways of circumventing the law on land conversion.

Lack of communication by HSRC with themunicipal government concerning subdivisionapplications caused development sprawl. Roadsbetween adjacent subdivisions were not coordinated. In 1986, the Sangguniang Bayan askedHSRC to carefully check the road plan beforeapproving any subdivision plan so that theroads to be built could be neatly integrated


with the existing network. Other subdivisionproblems later. became so intolerable that thetown officials were forced to request HSRC torefer the subdivision applications to the municipality before acting on them.

A number of reasons can be cited why consultations with the municipal government isnecessary before HSRC approves subdivisionplans. First,the local government has to provide services to the growing population, including the subdivision residents, and the properlocation of such services is of prime considerstion. Second, subdivision roads and open spacesare turned over to the municipality for maintenance and improvement and the municipalgovernment naturally would like to see that theroads are of acceptable standard. Third, thesubdivision plans may not be in agreement withthe objectives of the laryd use plan. Finally,if the municipal government is unaware of thenew subdivision, the lot buyers could constructbuildings without first applying for permit andthis may result in the loss of revenue. Severalbuildings without tax declarations were discovered in 1985 by the assessor's office aftertax-mapping activities were conducted in sixbarangays.

B. Preoccupation with Demands andComplaints of Residents

The Sangguniang Bayan spent most of itstime attending to the complaints and demandsof the residents from various sectors of thetown. Represented by the barangay Chairmenand leaders of private groups the residentsrequested !he allocation of funds for basketball courts, artesian wells, repair of roads, completion and repair of classrooms, health centerbuildings,and numerous others. The localgovernment, likewise, was asked to assume theduty of paying MERALCO for street lighting insubdivisions.

Citizen complaints often originating fromthe residents of subdivisions included nuisancecaused by foul odor from piggery, poultry, anddrying of fishmeal. The homeowners' associations would advise the Sangguniang Bayan notto accept the donation of roads and open spaceby developers of certain subdivisions due tonon-fulfillment of obligations to homeowners.

36

The land use plan was never a subject of theSangguniang Bayan's sessions since its approvalin 1980. The zoning ordinance, on the otherhand, was amended a few times. All the threeamendments as recorded in the minutes of theSangguniang Bayan were for the extension ofthe industrial zones. Subject to rezoning wereparcels formerly in agricultural use.

C. Lack of Personnel Trained inUrban Planning

The planning and development office ofthe municipality did not have anyone with abackground in urban planning. The staff ofthe office consisted of a lawyer, an engineer,electrician, and clerical assistants. The planningand development coordinator, who was alsothe civil registrar, had a public administrationexpertise. This may explain why the mattersusually discussed in the Sangguniang Bayansessions were administrative in character.

The planning office miserably lacked vitalinformation relevant to the understanding ofthe physical growth of the town. It did noteven have an official map to show the approvedland use plan. No system of monitoring thephysical changes in the different sectors of themunicipality was introduced. The assessor'soffice was better jnformed about subdivisionsand their locations. It had the summary of theuses of land of the whole town from 1980 to1982, althou~ the objectives of the assessorin keeping such data were different from thoseof the urban planner.

As regards the functions of the planningcoordinator enumerated in the Local Government Code, some of these were taken over byother officials. The local government officerfrom the Ministry of Local Government did theintegration and coordination of sector plans.Analysis of the municipal income and expenditure pattern of the municipality as well as theformulation of. fiscal plans and policies weredone by the budget officer. No progress wasmade insofar as promoting citizen participationwas concerned. The planning office found thebarangay chairmen disinterested in performingtheir job without compensation.

D. Political Affiliation of the Officials

The municipal mayor and majority of theSanggunaing Bayan members belonged to theopposition. The town officials apparently feltthe lack of support by the Marcos Administration because of their political differences.

There was a feasibility study made on themodernization of the public market in thepoblacion way back in 1981. The mayorsought loans in the amount of "7,000,000from the ditferent financial institutions of thenational government but he never got the loans.

The national highway between Balibagoand Tagaytay City was due for Widening andimprovement. The project had an appropriation approved by President Marcos. However,the mayor claimed, the fun<tJ for the projectwere diverted to other projects in Mindanao.

There could have been other setbackscaused by "politics" but this study did notdelve deeper on the problems. The informantswere hesitant to give information critical ofthe Marcos Administration.

CONCLUSION

It is not easy to evolve an effective municipal land policy under a set-up where thedevelopment of land is under the control of


central agencies. The objectives of the centralagencies may sometimes contradict the objectives of the local government. In their zeal tofulfill their functions the centralist plannersor technical personnel often fail to consultlocal "leaders. Whenever possible, certain functions should be decentralized to build thecapability of the local government to cope withdevelopment problems; more so if the localgovernment unit has shown signs of self-relianceand initiative.

Even at the present state (without decentralization) the local government should examinewhat can be done regarding the expansion ofthe town. The government unit must have in itsemploy an urban planner who is trained in landpolicy matters. This is especially true for themunicipalities at the periphery of MetropolitanManila. Without an urban planner or anyonewith sufficent knowledge of urban planning,the local officials might take courses of actiondetrimental to the future development of thetown. No one can advise the officials of thepossible consequences of their decisions.

The time for instituting a land policy is now.For some municipalities it might be a bit late,but innovative measures can be introducedto remedy the problems that are already there.It will be more costly to solve problems thatgrew because of neglect and inaction.

'~ sound land policy can direct development to a desired location. It cer

tainly has to be anchored on the land use plan which embodies the aspirations

and hopes of the residents. The land use plan can establish the scale of urban

expansion realizable within a specified period, judged on the local government

capacity to absorb the cost."

31

ECONOMIC VALUATION OF THEENVIRONMENTAL QUALITY EFFECTS

OF DEVELOPMENT

ZENAIDA A. MANALOAssociate Professor

School of Urban & Regional PlanningUniversity of the Philippines

INTRODUCTION

In the past, project analysis had given verylittle attention to the economic valuation ofenvironmental impacts of development projects.The reasons behind this may be summarizedinto two main points: the lack of adequateinterest in conserving the natural resource systems and the environment particularly on thepart of developing countries which have concentrated more on production and consumption targets; and the dearth of technical expertise which can enable analysts to factor environmental benefits and costs into the calculationof economic viability indicators like the Internal Rate of Return, Net Present Value, and theBenefit/Cost ratio.

Objectives of the Paper

This paper addresses the following objectives:

1. To highIight the global concerns expressedby various quarters regarding the adverseeffects of development on natural resourcesystems and the environment;

2. To present the attempts made thus far atincorporating environmental effects incost-benefit analysis;

3. To focus on two (2) specific economicvaluation techniques notably the cost-ef-

38

fectiveness and productivity techniqueswhich may be used in quantifying environmental benefits and costs; and

4. To show by way of some case illustrations from the Asia-Pacific region howthe above economic valuation techniquesare applied.

Scope of the Paper

Section I deals with the global concernsexpressed in international conferences sponsored by the United Nations and other U.N.affiliated agencies regarding the rapid depletionof natural resources and the degradation of theenvironment particularlv in developing countries. Section II shows how cost-benefit analysis(CBA) may be applied to include environmentalbenefits and costs. A brief inventory of economic valuation techniques is presented to showhow monetary values are assigned to environmental benefits and costs. Section III zeroes inon two (2) specific techniques, namely, productivity technique and cost-effectiveness an-

. alvsis, and provides two supporting case illustrations: The Coastal Development in TokyoBay, Japan and the TongonanGeothermalPlant in Leyte. Section IV gives the writer'sassessment of the prospects for the futureapplication of extended cost-benefit analysis,and Section V provides the concluding note.

I. THE GLOBAL CONCERNS OVER THEADVERSE EFFECTS OF DEVELOPMENTACTIVITIES ON NATURAL RESOURCESYSTEMS AND ON THE OVER-ALLENVIRONMENT

In 1969, The United States passed the National Environmental Policy Act (NEPA) in answer to a legitimate and essential need to protectthe environment. The Act required the preparation of a formal Environmental Impact Statement (EIS) for development projects. In 1972,the U.N. Conference on the Human Environment held in Stockholm expressed the worldwide concern that technological change wasoften accompanied by unanticipated damage tonatural resources and environmental quality.The conference made the environmentaland natural resource problems of developingcountries the object of global attention. Theconference called for the need -to have environmental policies and assessment procedures.

The concern for the environment permeatedmany other succeeding world conferencesnotably the following:

• U.N. World Population Conference inBucharest in 1974;

• U.N. World Food Conference in Romealso in 1974;

• Habitat: U.N. Conference on HumanSettlements in Vancouver in 1976;

• International Conference on the Survivalof Humankind in Manila in 1976;

• U.N. Conference on Desertification inNairobi in 1977; and

• UNESCO/UNEP Intergovernmental Conference 0/1 Environmental Education inrblisi in 1977.

From the above conferences emerged therecognition that "the critical environmentalresources of developing countries are todaysubject to stresses of unprecedented magnitude. Because the health, nutrition and generalwell-being of the poor ~jority are directlydependent on the integrity and productivityof these resources, the capability of governments to manage them effectively over the longterm may well be the single most importantprerequisite to the eradication of poverty, thefulfillment of basic human needs, and the ultimate achievement of sustained development.

39


Converselv, it is the poor who suffer mostfrom the failure to address these problemssuccessfully:,,1

After the Stockholm Conference, manycountries started to adopt environmentalpolicies and assessment methods. In the Philippines, on June 6, 1977, P.O. 1151 also knownas the Philippine Environmental Policy wasdecreed which required the preparation of anEIS for all projects, public or private, withsignificant environmental impacts. The policywas largely patterned after the U.S. NEPA.Earlier, on April 18, 1977, the National Environmental Protection Council (NEPC) wascreated via P.O. 1121 to serve as the pol icyformulating body on the environment. P.O.1586 was subsequently passed on June 11,1978 which institutionalized the PhilippineEIS system. The implementation of the EISsystem in the Philippines and elsewhere in thedeveloping world was plagued with a number ofproblems. These problems include the following:inadequacv of financial resources as well as thetrained manpower to effectively carry out theassessment; baseline data on natural resourcesystems are very limited; and, an essentialingredient to a successful EIS system is the aspect of public discussion of environmentalissues which in developing countries, particularly those under authoritarian leadership, hasbeen grossly absent.

In 1980, it was the U.N. EnvironmentalProgram (UNEP) Regional Office for Asia andthe Pacific which suggested .that a model forenvironmental assessment should include costbenefit anlysis. However, in the succeedingcase studies drawn up, the UNEP model was beset with problems such as double counting,neglect of shadow pricing and the like. Thereafter, the East-West Center, Environment andPolicy Institute (EAPI) spearheaded a programentitled: Natural Systems Assessment for Development (NSAD) which among others hasbeen undertaking the following:

1. Defining and quantifying the significantnatural systems factors that can limit thesuccess of development projects; and,

IUS AID. Environmental and Natural ResourceManagement in Developing Countries: A Report toCongress, Vol. I, (Washington, D.C.: US AID, 1979>,p.l0.


2. Evaluating these factors in economicterms for cost-benefit analysis.

The latter involves the techniques which attemptto valuate and monetize nonmarket environmental aspects of development. Some of thesetechniques will be discussed later in this paper.

II. THE INCLUSION OF ENVIRONMENTALBENEFITS AND COSTS IN COST-BENEFIT ANALYSIS (CBA)

Cost-Benefit Analysis, Some Basic Definitions:

A systematic method/technique of identifying and measuring the economic benefits and costs of a program or project.The benefits of a project are the valuesof incremental outputs of goods and services, including environmental services,made possible by the project, and thecosts are the values of incremental resources used by the project. 2

An estimation and evaluation of net benefits associated with alternatives forachieving defined public goals. 3

An approach rather than a techniquewhich provides a rational framework forproject choice using national objectivesand values. Projects are judged in termsof their precise impact on the economy,and this impact is evaluated by usingparameters reflecting national goals, social objectives and global facts. This definition is more in line with what is referred to as "social cost-benefit analysis,,4

For purposes of this paper, the first definitionis adopted.

2Maynard Hufschmidt, et. al., Environment,Natural Systems and Development: An EconomicValuation Guide, (Baltimore: Johns Hopkins University Press, 1983), p. 2.

3peter Sassons and William A. Schaffer. A CostBenefit Analysis: A Handbook, (New York AcademicPress, 1978), p. 3.

4UNIDO, Guidelines for Project Evaluation (NewYork: U.N., 1972), p, 14.

40

CBA, The Conventional View Vs The ExtendedView

Conventional CSA largely ignores off-site'or non-marketed gpods, services and effects.Extended CSA, stated simply, picks up the conventional approach and "extends" this to include a wider range of goods, services and effects, i.e., off-site, marketed and non-marketedgoods, services and effects. CSA applied in thismanner can assist in the protection and management of environmental quality. At the projectlevel, it can help to prevent projects from beingundertaken that might lead to reduced levels ofsocio-economic welfare because of damagesto the environment. An example follows toillustrate the on-site and off-site effects.

Illustration: Agricultunil activities

If the cropping pattern and farm management practices fail to consider the environment, more specifically, fail to address thesoil erosion problem adequately, the following on-site and off-site effects may arise:

On-Site Effects

Erosion affects soil productivity by reducing the available nitrogen in the soil and bydecreasing the moisture retention capacityof the soil. Soil loss translates to yield loss.The extent of damage depends on the soiltype and the soil depth. Even with fertilizerapplication, with soil erosion, crop yieldsdecline.

Off-Site Effects

With water-induced erosion, we have soilrunoff. Once soil runoff begins, the velocities and direction of the water over theland surface depend on the intensity andduration of the precipitation, the slope, thechannels and ditches of the conveyeancesystems, and the physical barriers to theflow. The runoff carries sediments or solidmaterials and oiher residuals from agricultural activities particularly from irrigatedagricultural activities such as nutrients(nitrogen and phosphorous). pesticides, andsalts which attach themselves to the soilparticles or are in dissolved form. Thesesediments and residuals find their way intothe water system. If the river system flows

into a reservoir, the off-site effects of thesedimentarydeposits in the reservoir causesreduced storaqe capacity, thereby causingreduced outputs of electrical energy andirrigation water, and increasing the potentialfor flood damages. Another off-site effects ofthe sedimentary and residual deposits in theriver system is the increased turbidity ofthe water leading to decreased fish production.The above illustration shows how important

it is to consider the environmental quality effects particularly off-site effects in the analysisof projects. The "Environment, Natural Systems and Development: An Economic Valuation Guide" prepared by the East-West Center,Environment and Policy Institute (EAPI)describes the following approach to the problem of economic valuation of environmentalquality effects of development projects. TheEAPI approach embodies- the following steps:

Step 1 - Identity the boundaries of theanaiysis. The boundary should be wideenough to include most major identifiableresults and effects but not so broad thatanalysis is impossible.Step 2 - Analyze the activity under consideration and identify all flow of goods andservices as well as effects on the environment.This includes the usual marketed goods andservices used or produced by the project aswell as less tangible, unpriced or off-sitegoods, services or effects.Step 3 - Quantify the identified effects.Any effect that cannot be valued or quantified can be retained as qualitative ratherthan quantitative information.StfJP 4 - After effects are quantified, monetary values are placed on these effects. Someof the techniques which may be used for thispurpose are covered by this article.Step 5 - Proceed with the over-all economicevaluation of the project including all directand indirect, on-site and off-site benefitsand costs. The resulting economic feasibilityindicators are NPV, IRR, and the BIC ratio.NPV is equivalent to the net benefit of theproject when all costs and benefits have beendiscounted to the present at the selected discount rate of interest. The IRR is the yieldor profitability of the project based on thediscounted cash flow analysis. IRR is thediscount rate which when applied to thestream of benefits and costs produces a

41


zero net present value. The BIC ratio is discounted benefits over discounted costs.Ideally, the ratio should be greater than

Economic Valuation Techniques which may beused in the Quantification of EnvironmentalBenefits and Costs

The follwoing presents a brief inventory ofavailable techniques which may be used inassigning monetary values to environmentalbenefits and costs:

1. Techniques based on actual marketprices ofgoods/services:

1.1. Productivity or market value technique - Measures the change in thevalue of the output using marketprices. In a watershed project, forexample, the environmental benefit may be increased production inthe lowland fields due to plentifulirrigation water. The value of theincremental production is the measure of off-sie effects of the project.

1.2 Earnings foregone or lossofearningstechnique - Quantifies the potential savings as benefits to be realizedby the project by improving the environmental conditions which resultto a decrease in illnesses and therefore less absences and greater earnings. Also included are savings onmedical expenses among the affected community residents. For example, a project which will installa new technology designed to correct the air pollution in a cementplant may use the technique described herein.

2. Techniques based on market prices ofenvironmental protection inputs:

2. 1 Cost-effectiveness analysis - Assesses the costs of actions that reduceexternal or environmental negativeeffects. It seeks the least cost ofmeeting a given goal. For example,for a project involving the settingup of a treatment plant to handle


the wastewater discharged by a textile mill which damages crops, fishery resources, and induces other environmental damages, cost-effectiveness analysis can assess variouswater treatment options in order toarrive at the most cost-effective solution.

2.2 Preventive expenditure technique This is based on the money spentby industries/firms/agencies tocounteract a negative environmental effect. In an airport example, astudy was done on the cost to beincurred by nearby residents tosoundproof their houses. These preventive expenses were then compared to alternative options thatmay be applied to decrease thesound generated by the aircraftssuch as installing sounds barriers,by initiating engine modificationsor undertaking runway realignment.The information on preventive expenditures were used to reach adecision on the control measure tobe adopted.

2.3 Replacement cost technique - Thisuses the costs of physically replacing damaged or lost goods/services and treats such costs as theminimum value of preventing theselosses. For example, for a soilconservation project in an uplandarea, mulching and land preparationtechniques were examined as ameans of reducing soil erosion. Theprimary benefit was a substantialreduction in 'the costs of replacingthe soil and the nutrients thatwould have been required in theabsence of any soil conservationproject. The costs of replacementwould have included the cost ofthe soil anll nutrients plus the truckservices and spreading costs.

3. Techniques based on surrogate markets:

3.1 Property value technique - Usesthe prices of land, houses and otherreal property to place a value on achanged environmental variable.

42

For an air pollution control project,for example, information on changesin property value based on a comparison of real properties in a polluted area .vs, real properties in a relatively pollution-free environmenttaking into consideration varyingdifferences in property characteristics such as number of rooms. typeof construction, access and othervariables provides an estimation ofthe benefits from decreased pollution.

3.2 Wage differentials technique - Forsome jobs which are hazardous, awage premium may be required toentice workers to accept such jobs,The' wage differential gives someindication of the value of compensation demanded because of theseenvironmental effects.

3.3 Travel cost technique - This technique which is often used in recreationprojects uses information on visitationrates and the cost of travelling to a site.From these two data inputs, a demandcurve may be constructed. from thedemand curve, the consumer surplusmay be determined. The value of theconsumer surplus gives an indicationof the benefits accruing from environmental improvement or maintenance.

4. Hypothetical Valuation Techniques:

These techniques question the people ontheir willingness to pay to retain an environmental good/service or their willingness to .accept compensation to give up their right.

4.1 Bidding game - The person interviewed participates in a biddingprocess to determine willingness topayor compensation demanded. Forexample, in a move to determinewhether a public park will continueto be kept open, users were askedif they were willing to pay a certainentrance fee to ensure this. If theresponse was positive, this initialamount was raised by a certainincrement until a negative responsewas obtained. Once this was reachedthe amount was correspondingly

lowered until a positive responsewas again reached. The average ofsuch positive responses multipliedby the number of park visitors peryear yielded the monetary value ofkeeping the park open annually.

4.2 Trade-off game - In this case, theperson interviewed is offered achoice between several goods, oneof which is an unpriced environmental good and the others aremarketed goods. In a particularcase, a person was asked if he preferred a certain amount of moneyor 20 percent reduction in the noiselevel for one year. Another personis asked, but this time, the amountof cash is different from the first(either higher or lower) but the20 percent noise reduction is retained. The information is collatedin order to estimate an average perperson value of the 20 percentnoise reduction.

III. PRODUCTIVITY OR MARKET VALUETECHNIQUE AND COST-EFFECTIVENESS ANALYSIS WITH SUPPORTINGCASE ILLUSTRATIONS

The choice of the two (2) techniques listedin the above is based on the relative ease andthe straight-forward manner of applying suchtechniques in quantifying environmental benefits and costs. Among the methods available,these two are also the most widely used. Productivity technique applies to the valuation ofenvironmental benefits while cost-effectivenessanalysis applies to environmental costs.

Productivity or Market Value Technique

The productivity or market value techniquealso referred to as the change in productivityapproach values the effects of development onthe natural system by measuring the increasein the physical productivity of the system orthe prevention of its deterioration over time.As such, the environmental benefits can eitherbe the increased production or the value ofdamages prevented. This method is commonlyapplied to watershed management projects,erosion control programs, reforestation programs and coastal development projects.

43


Case Illustration: The Valuation of Losses(Benefits Foregone) in Marine ProductResources caused by the Coastal Development of Tokyo BayS

Background Information:

Several decades ago, Tokyo Bay used tobe a very productive source of fish and seaweeds, and a popular recreation area. By the1970's, Tokyo Bay was already surroundedby highly industrialized and thickly populated areas (Tokyo, Kanagawa and ChibaPrefectures). In Tokyo Bay, one finds theheaviest shipping traffic in Japan. As may beexpected, the industrial development of thecoastal area has destroyed the coastalecosystem. The urbanization of the surrounding areas has also resulted in pollutedwater due particularly to the delayed sewerage system development.

In 1961, the Gobernor of Chiba Prefecture announced an ambitious industrialization plan which included land reclamationalong the seashore in Tokyo Bay. The landreclaimed from the sea was intended to serveas site for heavy industries. By the early1970's, the industrial profiles of Chiba,Tokyo and Kanagawa Prefectures have considerably expanded to include 13 oil refineries, 6 petrochemical plants and 12 otherchemical plants, 3 iron works, 10 automotive factories, 17 power stations and 10 shipyards. As a result, the productivity of thebay declined and to make up for the lostproductivity, compensation payments weremade to the fishermen.

Procedures Used: The lesson to be learnedfrom the environmental degradation ofTokyo Bay may be quantified by using theproductivity technique, which in turn, canserve as lfaluable inputs to the planning of

5Yuzuru Hanayama and Ikuo Sane, "Valuation ofLoses of Marine Product Resources Caused by CoastalDevelopment of Tokyo Bay" in Economic ValuationTechniques for the Environment: A CaseStudy Workbook, eds., John A. Dixon and Maynard M. Hufschmidt, (Baltimore: The Johns Hopkins UniversityPress, 1986), pp. 102-120.


other similar coastal development projectsin the future.

The task at hand is the estimation of theeconomic value of the marine product resources destroyed by the development inTokyo Bay over a given period. The economic valuation procedures used may be outlined as follows:

1. Estimate the decline in physical productivity of the marine product resources from the start of the coastaldevelopment to the present based onthe assumption that such decline hasbeen largely due to the urban and industrial developments in the bay;

2. Using market prises, attach an economic value to the lost productivity.Make assumptions as to future marketprices for marine products and thenestimate the future annual economicvalue of the lost productivity.

3. Convert all values to a common pricelevel. The annual value of the lost resources would be the market value ofthe lost annual output less the estimated capital and operating. costs ofproducing the output.

4. Compute the present value of this annual value using one or more assumeddiscount rates.

A major issue in the application of thetechnique is the treatment of the fishermen'slabor, Le., whether at market wage rate or ata shadow price which may be zero. Following the outlined procedures, the case studyyielded cumulative productivity losses of 52billion yen at 1979 prices. This approximatesthe negative environmental effects (in termsbenefits foregone) of the industrial andurban developments in Tokyo Bay on thecoastal marine resources.

Cost-Effectiveness Analysis (CEA)

CEA as applied to environmental qualityseeks to anlyze alternative ways of reducing theadverse effects of residuals and discharges onthe natural system. Its main objective is toarrive at the least or minimum cost of effectively handling such adverse effects on the environment. The geothermal example given belowshows how CEA is used.

44

Case Illustration: Alternative Waste FluidDisposal Schemes: Tongonan GeothermalPower Plant6

Background Information:

The Tongonan geothermal plant lies within the catchment area of upper Mahiao andSambaloran Rivers, north of Orrnoc City inLeyte. Exploration drilling in Tongonanbegun in December 1973 and by July 1977,the first deep well was connected to a 3MW turbine. In 1978, it was confirmed thatthe Tongonan field represented an exploitable geothermal resource. Because of the reservoir potential, the power plant was expanded under Phase I of the project. Steamwill be supplied by as many as 15 wells andwill flow in 2-phase pipelines to separatorstations. Fluids and steam will be separatedin these stations..The fluids will then be disposed of through a waste water disposalsystem.

The operation of the power plant usingthe steam geothermal resources will produceresidual geothermal waste fluids and gases.These residuals have chemical and thermalcharacteristics that may have adverse effectson the environment depending upon the rateand frequency of discharge and the schemeof waste disposal adopted.

The geothermal waste fuids contain largequantities of arsenic, boron and lithium.Arsenic can exert detrimental effects onfishery productivity by impairment ofgrowth and other physiological functions.Arsenic can also reduce crop yields. Beyonda certain limit, boron in drinking water mayinterfere with the digestive processes of man.For plants and animals, boron can be verytoxic. For lithium. it may have adverseeffects on the delta and marine ecosystems.Although the geothermal fluids from Tongonan contain very low levels of mercury, itseffects on the environment should also be

6 Beta Balaqot, "Tongonan Geothermal Power PlantProject in Leyte" In Economic Valuation Techniquesfor the Environment: A Case Study Workbook, " eels.John A. Dixon and Maynard M. Hufschmidt, (Baltimore: The Johns Hopkins University Press, 1986) pp..83-101.

monitored. In humans, methelmercury isneorotoxic and is only slowly excreted fromthe system: On marine resources, studiesindicate that the presence of mercury atvery low levels in the aquatic ecosystem candisrupt the complex interdependency between phytoplankton and the populationthat feed them. Mercury concentration lessthan 0.01 mg/lt have caused sublethal effects such as growth retardation, reductionof egg production and hatchability andembryo deformities in fish. Low concentration of mercury can produce genetic aberrations in some animal species.

Procedures Used: The use of CEA in thegiven example is directed at arriving at themost cost-efficient solution to the wastedisposal problem. As such, unlike the productivity technique which is applied in theestimation of environmental benefits, CEAaddresses the quantification of environmental costs. In the Tongonan power plant,several alternative wastewater disposalschemes were evaluated. These included thefollowing:1. Heinjection c- Geothermal fluids from se

parator stations will be piped to reinjection wells within the field.

2. Discharge to Mahiao River without treatment - Simply involves the retention ofthe waste fluids in a thermal pond for afew days prior to discharge.

3. Discharge to Mahiao River with treatmentfor arsenic removal - Same as alternativeno. 2 except that the thermal pond istreated with chemicals to remove thearsenic.

4. Discharge to Bao River without treatrnent.e- Same as no. 2.

5. Discharge to Bao River with treatmentfor arsenic removal - Same as no. 3.

6. Disposal at sea with outfall at BiasongPoint - A 32-km pipeline will be constructed to the outfall site to be able todischarge the geothermal wastewaterdirect to the sea.

7. Disposal at sea with outfall at Lao Point- Essentially the same as no. 6 exceptthat it involves the construction of a22-km pipeline.

Conventionally, CEA will include only thecapital costs (construction of pipelines, thermalponds and the other components of the purification system) and operating and maintenance

45


costs for each of the given alternative. Whenwe consider the effects on the natural system,we then expand the conventional approach toinclude envrionmental costs, Without the treatment of the residuals, the discharge of theuntreated geothermal waste fluids to the riversystem is expected to affect the productivityof the fields serviced by the existing irrigationsystems due to the high levels of arsenic andboron. The loss in productivity representspart of environmental costs. An additionalenvironmental cost is the risk to health ofhumans and livestock from using pollutedriver water. Another environmental cost is theadverse effects on the marine life in the areadue to water pollution. The effects on the marine ecosystem may be estimated by usingfishery productivity data. The procedures outlined under productivity or market valuetechnique should be followed. Aside from thehealth effects which are difficult to quantify,the productivity losses may be easily quantified by getting the effects of varying levels ofwater quality on crop and fishery yields. Acomparison of yields may be made based onwith and without treatment and at varyinglevels of treatment. We are aiming at the wastedisposal scheme which minimizes the environmental losses to the lowest possible level. Inthis case, alternative no. 5 (Discharge at BaoRiver with treatment for arsenic removal) wasfound to be the most cost-effective and environmentally sound.

IV. THE PROSPECTS FOR THE FUTURE USEOF EXTENDED COST-BENEFIT ANALYSIS

The incorporation of environmental considerations in development planning has notreceived strong support in most developingcountries. This view may be atrributable tosome misconceptions such as:

• The environmental degradation was principally a problem of rich countries,commonly referred to as the "effluentsof affluence";

• Environmental problems in poor countries reflected a lack of development;

• There was an unfavorable trade-off between economic growth and the maintenance of environmental quality;

• Poor countries cannot afford to divertresources which are essentially scarce toenvironmental protection; and,


• The political view that focusing on thepreservation of the environment may bea ploy of rich industrial countries to deliberately keep the Third World at primitive stages of development." .

In the decade of the 80's what confronts useven more vividly than in the past is the realization that we cannot sustain development if wecontinue to disregard the environment. Forone, scarcity of resources in poor countriesimplies a very high value for such resources,hence, the need to judiciously conserve these.Secondly, economic production in developingcountries particularly in agriculture, fisheryand forestry requires that the productive capacities of natural systems to regenerate growth isinsured.

In this context, economic analysis, especiallyextended cost-benefit analysis, can be used todetermine optimum environmental controlmeasures. The problem in the recent past isthe difficulty in translating into monetary valuesome environmental damages avoided. Asshown in the earlier sections, some gains.havebeen achieved in this direction.

In the past development decade, developingcountries have concentrated more on projectswith high impacts or immediate economicbenefits with some detrimental effects on theenvironment. However, environment and economic development should not necessarily be

7Charles Pearson and Maynard M. Hufschmidt,Incorporating the Environment in DevelopmentPlanning: A Report of Work at the East-West Environment and Policy Institute, (Honolulu: East-WestCenter, 19781. p. 2.

46

at odds aqainsteach other but rather, that eachshould support the other. In view of this, themove to fuse environmental economics anddevelopment planning has begun. With the recent action of international funding agenciesparticularly the Asian Development Bank ininputing environmental factors in projectanalysis, if sustained, we can hope to be a stepcloser at ensuring a healthy environment forour future generations.

V. CONCLUDING NOTE

For economists, the challenge is how tointegrate economic analysis with scientific andtechnical analysis in the generation of naturalsystem and environmental. quality impacts ofeconomic activity. We cannot stay just withinthe confines of our own discipline and remainoblivious to the detrimental effects of somedevelopment projects on the natural system.For the economist-planner, the challenge iseven bigger inasmuch as our professional responsibility goes beyond economic planningto encompass land use planning. It is in thelatter that environmental factors come significantly into play. Promoting environmentalconsciousness within our ranks is. certainly afirst step. Disseminating technical informationon the environment is the next step. For useducators in planning and economics, thesetasks become very urgent before time runsouts.


"We have to act fast! If we do not heed the pleas of the government and those concerned tosafeguard our forests, where will we go?"

PHOTOGRAPHED BY PROF. ERNESTO M. SEROTE

47


ABOUT THE CONTRIBUTORS·

SIROUS SALJOUGHIAN ESFAHANlis a graduate student in the School ofUrban and Regional Planning, University of the Philippines. He holdstwo B.S. degrees from Mapua Institute of Technology: one in CivilEngineering and the other in Environmental and Sanitary Engineering.

ROMEO C. BRUCE is a Professor in Photo Interpretation in the TrainingCenter for Applied Geodesy and Photogrammetry of the UP Collegeof Engineering. He holds the degrees of Bachelor of Science in Agriculture from the University of the Philippines, M.S. in Agronomyfrom the University of Illinois and a Ph.D. in Agronomy and SoilScience from the University of Hawaii. He also had extensive trainingabroad in soil mapping, land classification and an advance course in airphoto interpretation and remote sensing in Cornell University.

He has actively served as land-use planner and consultant inremote sensing and photo interpretation to public and private institutions here and abroad. Many of his research work have been published.

TITO C. FIRMALINO is Professor of Environmental Planning at the University of the Philippines. He holds two master's degrees: one inPublic Administration from the University of the Philippines and theother in Community and Regional Planning from the University ofBritish Columbia, Vancouver, Canada. He was recipient of the BritishCouncil Fellowship Grant to attend the Special Course in UrbanPlanning in the University College London. For a time, he was a member of a United Nations team which assisted the Prime Minister'sOffice of Tanzania in the preparation of training programs designed toupgrade planning skills of planners and planning assistants at thedistrict and regional levels.

He has written numerous articles in the fields of public administration and town and country planning.

ZENAIDA A. MANALO is Associate Professor .of Urban and RegionalPlanning at the University of the Philippines. She obtained herBachelor of Arts degree major in Economics from the University ofthe Philippines. She also holds two master's degrees: one in Economicsfrom the Ateneo de Manila University and the other in Urban andRegional Planning (with specialization in the areas of Urban Planningand Estate Planning) from the University of the Philippines. In 1979,she was selected as the first fellow from the Philippines of the HubertH. Humphrey North-South Fellowship Program which is under theauspices of the Fulbright Exchange Program. This fellowship gave herthe opportunity to attend the Special Program in Urban and RegionalPlanning (SPURS) of Developing Countries at the Massachusetts Institute of Technology in Cambridge, USA from which she earnedseventy-five (75) graduate units. She is currently a Ph.D. candidate inUrban and Regional Planning at the School of Urban and RegionalPlanning, University of the Philippines.

She has served as Professional Associate at the East-West Center,Environment and Policy Institute, Honolulu in 1980, 1982 and 1983.She has also served as consultant in the fields of economics, urban andregional planning and population to numerous public and privateentities.

48

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